- Weston A. Price (Nourishing Traditions) Diet
- Paleo Diet
- Primal Blueprint
- Animal-Based Diet
- Carnivore Diet
- Ketogenic Diet
- Atkins Diet
- South Beach Diet
- Zone Diet
- Dukan Diet
- Low-Carb High-Fat (LCHF)
- Bulletproof Diet
No. 41Weston A. Price (Nourishing Traditions) Diet
In the 1930s, dentist Dr. Weston A. Price visited isolated communities on several continents and reported that people on traditional diets had fewer cavities than neighbors eating white flour and sugar (Nutrition and Physical Degeneration, 1939). A dentist against sugar: some things never change. Sally Fallon Morell and Mary Enig, authors of the cookbook Nourishing Traditions, founded the Weston A. Price Foundation in 1999. The diet favors organ meats, bone broth, raw and cultured dairy, soaked, sprouted or fermented grains, butter, lard and tallow, and cod liver oil.
Strengths
- Rich in vitamin A, vitamin B12, iron, zinc and choline from organ meats and eggs.
- Soaking, sprouting and fermenting can make grains easier to digest and lower phytic acid, which helps mineral absorption. Slow kitchen habits, with a payoff.
- Firmly rejects refined sugar, white flour, refined seed oils and ultra-processed food. No neon-colored snacks allowed.
Watch out for
- Dr. Price's work was observational, not controlled trials, and many things besides diet differed between the groups. The diet as a whole has not been tested in trials.
- Raw milk can carry germs such as Listeria, E. coli and Salmonella. US health agencies advise against it.
- Liver plus cod liver oil can add up to too much vitamin A, a concern in pregnancy. Even good things can pile up.
- Lots of saturated fat raises LDL cholesterol in some people.
- It can take a lot of time and money. Fast food it is not.
Eating well within it
- Eat liver in modest portions; mixing some into ground beef makes it easier, and nobody at the table has to know.
- Choose yogurt, kefir, aged cheese or pasteurized whole milk if raw milk is not safe for your household.
- Bake sourdough, soak oats or beans overnight, and keep vegetables plentiful.
Possible supplement needs
The foundation promotes cod liver oil. Count it toward your vitamin A and D totals, especially in pregnancy and alongside liver.
Who should be careful
Pregnant women, young children, older adults and anyone with weakened immunity (raw milk); people with high LDL cholesterol.
In depth
Dr. Weston A. Price and traditional diets
Dr. Weston A. Price was an American dentist who, in the 1930s, traveled to isolated communities around the world: Swiss mountain villages, Gaelic islands off Scotland, Inuit communities, Pacific Islanders, Maori, African herding peoples, and Indigenous peoples of North and South America. He published what he saw in Nutrition and Physical Degeneration (1939).
- What he reported. People eating their traditional foods had very few cavities, broad dental arches with room for all their teeth, and good health. When the same groups switched to what he called "the displacing foods of modern commerce" (white flour, sugar, canned goods and vegetable oils), cavities and crowded teeth appeared within a generation.
- No single traditional diet. The Swiss ate raw dairy and rye; the Inuit ate fish, seal and almost no plants; the Maasai ate milk, blood and meat; Pacific Islanders ate seafood, coconut and root vegetables. What they shared was whole food, prepared by tradition, and some animal foods in every group, often including organ meats, fish eggs or butter from grass-fed animals.
- Fat-soluble vitamins. Price found that traditional diets were far richer in vitamins A and D than the American diet of his day, and he described an unknown fat-soluble nutrient he called "Activator X," found in grass-fed butter, organ meats and fish eggs. In 2007 the researcher Chris Masterjohn proposed that Activator X is vitamin K2. That is a strong hypothesis, not a proven fact.
The limits of his work. Price's findings are observations, not controlled studies. He compared groups that differed in many ways besides diet, and some of his other dental theories have not held up. Teach what he observed, and say that it is observation.
*Nourishing Traditions*: traditional preparation
In 1999, Sally Fallon (now Sally Fallon Morell) and the fat researcher Dr. Mary Enig founded the Weston A. Price Foundation to carry Price's work into modern kitchens. Fallon's Nourishing Traditions is part cookbook, part argument. Its core principles:
- No refined or ultra-processed foods. No white flour, refined sugar, refined vegetable oils or additives.
- Animal foods, including organ meats and their fats. Liver is one of the most nutrient-dense foods there is.
- Bone broth, made by simmering bones for hours, for minerals and gelatin.
- Lacto-fermented foods such as sauerkraut, kimchi, kefir and yogurt.
- Grains, beans, nuts and seeds soaked, sprouted, fermented or naturally leavened (sourdough). Seeds contain phytic acid, which binds minerals. Soaking, sprouting and fermenting lower phytic acid and make iron and zinc easier to absorb. This is well supported by research.
- Traditional fats: butter, ghee, lard, tallow, olive oil and coconut oil, with little polyunsaturated oil.
- Unrefined salt, and special nourishing foods for parents-to-be and young children.
Raw milk. The Weston A. Price Foundation promotes raw (unpasteurized) milk. The FDA and CDC warn that raw milk can carry Listeria, E. coli, Salmonella and Campylobacter. Whatever a client decides for themselves, raw milk and raw-milk cheeses are a firm no for pregnant women, babies and young children, older adults and anyone with a weakened immune system (see the Coach's Safety Notes).
No. 42Paleo Diet
The paleo diet tries to copy what people ate before farming began, minus the spear: meat, fish, eggs, vegetables, fruit, nuts and seeds. It cuts out grains, beans and other legumes, dairy, refined sugar, refined seed oils and processed food. Dr. Loren Cordain, a professor of exercise science, made it popular with his book The Paleo Diet (2002), arguing that the human body is not adapted to foods that came with farming.
Strengths
- Removes most ultra-processed food, refined sugar and refined oils. Cave dwellers had no snack aisle.
- Plenty of protein, vegetables and fruit helps many people feel full and eat less.
- Small trials have found improvements in weight, blood sugar and blood pressure over short periods. Larger, longer studies are still lacking.
Watch out for
- Scientists point out that ancient diets varied widely by place and season. Some hunter-gatherers ate many starchy roots, honey or wild grains, so there was no single "paleo diet" (and nobody was selling one).
- Beans and whole grains are linked in many studies to longer life and lower heart risk. Cutting them removes good sources of fiber.
- Without dairy, calcium can run low unless you eat greens, canned fish with bones and nuts.
- Store-bought "paleo" snacks and baked goods can be as processed and sweet as what they replace. A caveman cookie is still a cookie.
- Most weight loss comes from eating less, and long-term results depend on sticking with it.
Eating well within it
- Fill half your plate with vegetables, including sweet potatoes, squash and plantains.
- Eat sardines or salmon a few times a week.
- Cook with olive oil, avocado oil or tallow instead of refined seed oils.
Possible supplement needs
Calcium and vitamin D, along with iodine if you avoid iodized salt.
Who should be careful
People with kidney disease (high protein), those at risk of low bone density, and anyone with a history of disordered eating.
No. 43Primal Blueprint
Former endurance athlete Mark Sisson laid out this approach in The Primal Blueprint (2009) and his blog Mark's Daily Apple. It is close to paleo, a more relaxed cousin: meat, fish, eggs, vegetables, fruit, nuts and healthy fats, with no grains, refined sugar or refined seed oils. Unlike strict paleo, it allows some full-fat dairy, dark chocolate and an occasional glass of red wine. It also sets out lifestyle "laws," such as moving often at a slow pace, lifting heavy things, sprinting now and then, sleeping well, getting sunlight and playing. Finally, a law that tells grown-ups to play.
Strengths
- Looks at the whole person, not just food: movement, sleep, sunlight and play all count.
- Whole-food base with little sugar or ultra-processed food.
- More flexible than strict paleo. Sisson's "80/20" idea (do your best most of the time) can make it easier to keep up, since nobody is perfect anyway.
Watch out for
- The diet has not been tested as a whole in research. Evidence for its parts (more vegetables, less sugar, regular exercise) comes from other studies.
- Like paleo, it drops grains and limits legumes, which are linked in studies to good health and supply fiber.
- It can drift toward very high fat and low carbohydrate. That suits some people but not others, such as heavy exercisers.
- Weight loss still depends on eating less overall and sticking with it. No blueprint gets around that.
Eating well within it
- Choose plain whole-milk yogurt, kefir or aged cheese if you include dairy.
- Build meals around vegetables and a palm-sized portion of protein.
- Walk daily and add two short strength sessions a week, as the plan suggests. The couch will manage without you.
- Eat enough starchy vegetables or fruit if you train hard.
Possible supplement needs
Vitamin D if sun is limited; calcium if you skip dairy.
Who should be careful
People with kidney disease, those with high LDL cholesterol, and anyone with a history of disordered eating.
No. 44Animal-Based Diet
Dr. Paul Saladino, a physician, first promoted a strict carnivore diet in The Carnivore Code (2020). He later moved to what he calls an "animal-based" diet, which is carnivore with a fruit bowl: meat, organ meats, eggs, raw dairy, fruit and honey, with few or no vegetables, grains, beans, nuts or seeds. He argues that many plants contain defense chemicals that can bother sensitive people, while fruit and honey are gentle sources of carbohydrate.
Strengths
- No ultra-processed food, refined sugar or refined seed oils.
- Organ meats and eggs supply vitamin A, B12, iron, zinc and choline.
- Fruit and honey make it easier to follow than strict carnivore, and supply vitamin C and potassium.
Watch out for
- There is almost no research on this exact diet. Support comes mostly from personal stories, and testimonials are not trials.
- The idea that vegetables are harmful runs against a large body of research linking vegetables, beans and whole grains with lower risk of illness. Broccoli has a better track record than its critics.
- Fiber is low unless you eat a lot of fruit.
- Raw milk can carry harmful germs such as Listeria, E. coli and Salmonella. US health agencies advise against it.
- Large amounts of saturated fat can raise LDL cholesterol in some people.
Eating well within it
- Eat a wide range of fruits, including berries, citrus and kiwi, for fiber and vitamin C.
- Choose cultured or pasteurized dairy if raw milk is not safe for you.
- Include fatty fish, not only red meat, for omega-3 fats and iodine.
- If you tolerate them, consider adding some cooked vegetables such as squash. They come in peace.
Possible supplement needs
Usually few, but iodine and vitamin D are worth checking, plus calcium if dairy is skipped.
Who should be careful
Pregnant women, children, older adults and anyone with weak immunity (raw milk); people with high LDL cholesterol, gout or kidney disease.
In depth
Dr. Paul Saladino: *The Carnivore Code*
Dr. Paul Saladino is a physician trained in psychiatry. The Carnivore Code (2020) argues:
- Plants defend themselves with chemicals such as oxalates, lectins, phytates, isothiocyanates (like sulforaphane in broccoli) and some polyphenols, and these can harm sensitive people.
- Animal foods are the most nutrient-dense foods, supplying nutrients that are scarce or absent in plants, such as vitamin B12, heme iron, zinc, retinol, creatine, carnitine, choline and taurine.
- Eat "nose to tail," including organ meats such as liver, and bone broth, not just muscle meat. He describes tiers from mostly animal foods with a few "least toxic" plants to an all-animal diet.
His later change. In the early 2020s Saladino moved away from strict carnivore to what he calls an "animal-based" diet: meat, organs and dairy plus fruit and honey. He reported that long-term strict carnivore did not suit him and has said long-term ketosis is probably not best for most people. It is a useful example of a teacher adjusting his own approach.
Where others disagree. Many plant compounds Saladino calls toxic, including sulforaphane, are studied for their health benefits, and diets rich in vegetables and fruit are linked with lower rates of many diseases. Saladino also promotes raw milk and has eaten raw organ meats, which carry a real risk of infection (see the Coach's Safety Notes).
No. 45Carnivore Diet
The carnivore diet means eating only animal foods: beef and other meats, fish, eggs, and for some people butter and cheese. All plant foods are removed, including vegetables, fruit, grains, beans, nuts and seeds. Yes, even the parsley garnish. Well-known voices include orthopedic surgeon Dr. Shawn Baker, family physician Dr. Ken Berry, nutritional therapist Judy Cho (Carnivore Cure), and Dr. Paul Saladino's earlier work.
Strengths
- No ultra-processed food, sugar or refined seed oils, and it is simple to follow. The shopping list is short.
- Supplies complete protein, vitamin B12, iron and zinc.
- Removing foods can help some people find what bothers them. A 2021 survey led by Harvard researchers of 2,029 people on the diet found most reported better health, weight and satisfaction.
Watch out for
- That survey relied on self-reports from people recruited online who were happy enough to keep going. Think customer review, not clinical trial: it cannot prove the diet works or is safe.
- There are no randomized trials of the carnivore diet.
- In the same survey, many people had high LDL cholesterol. Over years this may raise heart risk.
- Uric acid can rise, which can trigger gout. People with kidney disease may be harmed by very high protein.
- Fiber, vitamin C, folate and potassium may run low. Constipation is common, a side effect few influencers post about.
Eating well within it
- Eat organ meats such as liver weekly for vitamin A, folate and some vitamin C.
- Include fatty fish, not only beef.
- Choose fresh meat over bacon, sausage and deli meats.
- Some people find a looser approach, adding a little fruit or vegetables, easier to sustain. A blueberry is not a betrayal.
Possible supplement needs
Magnesium, potassium, vitamin C and iodine are the ones that run short.
Who should be careful
People with kidney disease, gout, high LDL cholesterol or heart disease, pregnant women, children, and anyone with a history of disordered eating.
In depth
How an elimination diet works
An elimination diet is an experiment, not a lifelong menu. It has three steps:
- Remove the foods most likely to cause reactions, for a set time (usually 3 to 6 weeks, sometimes longer).
- Wait and track. Record symptoms daily: energy, sleep, mood, digestion and stool, skin, joint pain and, for women, the menstrual cycle.
- Reintroduce foods one at a time, a few days apart, watching for a reaction. Foods that cause symptoms stay out for now; the rest come back.
Common elimination diets include Whole30 (30 days without grains, legumes, dairy, sugar and alcohol), the autoimmune protocol (AIP, which also removes eggs, nuts, seeds and nightshades), low-FODMAP for IBS (best done with a dietitian), GAPS (see Before the Diets: Whole Food and the Gut) and carnivore.
Rate symptoms with numbers. Judy Cho teaches clients to rate each symptom from 1 to 10 rather than writing "yes" or "no." A drop from 6 to 4 in joint pain is real progress that a yes-or-no journal would miss.
Food allergies are different. A true allergy (hives, swelling, wheezing, vomiting soon after eating) can be life-threatening. Those foods are never reintroduced at home; that happens only with an allergist.
The carnivore diet
The carnivore diet is made up only of animal foods: beef, lamb and other meats, fish and seafood, eggs, animal fats, and for some people dairy, with salt and water. Most people who follow it eat two meals a day of fatty meat, often beef, and some add organ meats and seafood.
Why people try it. People most often try carnivore for autoimmune conditions, gut problems, mood and mental health, skin conditions, weight and blood sugar. Supporters, such as family physician Dr. Ken Berry, argue that animal foods supply nearly every nutrient in its most absorbable form, while some plant foods contain compounds that irritate sensitive people. Removing all plants at once also makes carnivore the simplest elimination diet there is.
Judy Cho: *Carnivore Cure*
Judy Cho is a holistic nutritionist. On a low-fat vegetarian diet, she struggled with depression, anxiety, an eating disorder and severe postpartum depression. Keto helped, and an all-meat diet helped most. Carnivore Cure (2020) presents carnivore as an elimination diet, the approach she uses in her practice and explains in the video.
Her protocol, in phases. Not everyone needs to start at phase 1; it is for people who still feel unwell on an ordinary carnivore diet.
| Phase | Foods |
|---|---|
| 1 | Ruminant meats only (beef, lamb, bison, venison, elk), limited organ meats, fat from those animals, unrefined salt and filtered water |
| 2 | Adds turkey, egg yolks, and ghee or cultured butter |
| 3 | Adds pasture-raised chicken |
| Later | Conventional (not grass-fed) meats, then, to test tolerance, cured and processed beef and poultry |
- Reintroduce one food at a time. She suggests a small portion of the new food at one meal (for example, half a cup of boiled chicken at lunch), noting sleep, stool, mood, energy and hormones, and, if all is well, more the next day.
- Change one thing at a time, including the cooking method; boiled chicken and air-fried chicken can be tolerated differently.
- Eat enough. The most common problem she sees is under-eating; she warns against diets of 1,400 calories and also that people can gain weight on carnivore if they overeat.
- Histamine. For sensitive people she limits high-histamine foods early on, such as long-cooked bone broth, ground beef, aged and cured meats, and fermented foods (compare the GAPS Diet).
- Carnivore is not always the whole answer. If someone can only tolerate a few meats long-term, she looks for other causes with their practitioner rather than staying on a narrow diet forever.
What the evidence shows
- The Harvard survey (2021). Researchers at Boston Children's Hospital and Harvard surveyed 2,029 adults who had eaten a carnivore diet for a median of 14 months. Most reported better health, weight loss and, in those with diabetes, lower blood sugar and less medication, and few side effects. Their LDL cholesterol was high (a median of 172 mg/dL), while HDL and triglycerides were favorable. Judy Cho quotes this study in the video.
- Its limits. The people chose to answer, were recruited from carnivore social-media groups, and reported their own results, with no comparison group. A survey can show what people experienced, not what caused it.
- No controlled trials yet. A 2026 review found only nine small human studies and no randomized trials. The risks it found were rising LDL cholesterol, gout flares, kidney-stone risk, very low fiber, and, in diet calculations, possible shortfalls of vitamin C, thiamine, magnesium, calcium, potassium and iodine. No cases of scurvy were reported; whether people on carnivore need less vitamin C is still debated.
- In the video, Dr. Peter Attia and Dr. Stephan Guyenet review the carnivore diet critically: no trials, the "plants are toxic" argument goes too far, and LDL cholesterol rises sharply in some people.
A fair summary for clients: "Many people report real improvements, and carnivore can be a useful elimination diet. We don't yet have long-term studies, so we use it as a time-limited experiment, track how you feel, and check your labs before and after."
Coaching a carnivore or elimination diet
- Set the purpose and a time frame: for example, 30 to 90 days to see whether symptoms improve, followed by reintroduction.
- Labs before starting and after about three months (a coach does not order or interpret them, but you can teach clients to order their own and read the results): lipids, uric acid, kidney function, and HbA1c or blood sugar where relevant.
- Make it nutrient-dense: fatty cuts, eggs, fish (sardines, salmon), and some liver or other organ meat, not lean ground beef alone.
- Enough fat, protein and calories, and salt and water, especially in the first weeks (the same "keto flu" as in the Ketogenic Diet entry).
- Digestion often changes in the first weeks; loose stools and constipation usually settle. Easing in over a week or two helps.
- Track and reintroduce: a 1-to-10 symptom journal, then one food at a time.
- Watch the relationship with food. Tracking and strict rules can feed obsessive eating in some people. If a client seems anxious or fearful around food, pause and refer.
Safety notes
- Eating disorders: a current or past eating disorder means no strict elimination or carnivore diet without the client's therapist or eating-disorder specialist on board.
- Kidney disease: a high-protein diet can strain damaged kidneys, so strict carnivore is not for them.
- Gout: carnivore can trigger flares; teach clients with gout to order a uric acid test before and after, and ease in.
- Heart disease and high LDL: LDL can rise sharply; teach clients to order a lipid panel before starting and after about three months.
- Medications: diabetes and blood pressure medication doses often need to come down, and only the prescriber changes them, exactly as with keto; thyroid medication may need adjusting too.
- Pregnancy, breastfeeding and children: no strict carnivore or elimination diet; they need a varied, nourishing diet.
- Raw meat, raw organ meats and raw milk: risk of serious infection; never for pregnant women, children, older adults or anyone with weakened immunity.
- True food allergies: never reintroduced at home; only with an allergist.
- Gallbladder problems or no gallbladder: a very high-fat diet may not be tolerated; ease in slowly.
No. 46Ketogenic Diet
A ketogenic ("keto") diet is very low in carbohydrate, moderate in protein and high in fat. With little carbohydrate coming in, the liver turns fat into ketones for fuel, a state called nutritional ketosis. Dr. Russell Wilder of the Mayo Clinic named it in 1921 as a therapy for epilepsy, long before it had a hashtag. Today it is widely used for weight loss and blood sugar; Dr. Josh Axe promotes "clean keto" (whole foods only) and "keto cycling" (adding more carbohydrate on some days).
Strengths
- A medical keto diet, run by a specialist team, is an established therapy for some children and adults with epilepsy that medicines do not control.
- Trials show it can lower blood sugar and triglycerides and help weight loss, at least in the short term.
- Many people feel less hungry on it, so the cookie jar loses some of its pull.
Watch out for
- "Keto flu" (headache, tiredness, cramps) is common in the first weeks, often because of lost water and salt.
- People on diabetes medicines, especially insulin, sulfonylureas or SGLT2 inhibitors, can face dangerous lows or a rare form of ketoacidosis, so their medicines need adjusting before they start.
- LDL cholesterol rises sharply in some people.
- Fiber, magnesium and potassium can run low. Many "keto" bars, shakes and desserts are ultra-processed: junk food with a new label.
- Most weight loss comes from eating less, and results depend on sticking with it.
Eating well within it
- Fill up on low-starch vegetables such as greens, broccoli, cauliflower and zucchini. Cauliflower has never been so busy.
- Choose olive oil, avocados, nuts, eggs and fish over processed meats and keto snacks.
- Salt food to taste and eat potassium-rich avocados and greens to ease keto flu.
Possible supplement needs
Sodium, potassium and magnesium (electrolytes) ease the first weeks. With kidney or heart conditions, extra potassium and magnesium can build up to dangerous levels.
Who should be careful
Anyone on diabetes or blood-pressure medicines, pregnant or breastfeeding women, people with kidney, liver or pancreas disease, and those with high LDL cholesterol.
In depth
What ketosis is
When carbohydrates are kept very low, insulin falls and the liver turns fat into ketones (mainly beta-hydroxybutyrate, BHB). The heart, muscles and brain can run on ketones. This state is nutritional ketosis, the same state the body reaches during a fast (see Intermittent Fasting), but while eating.
- Nutritional ketosis: blood ketones of about 0.5 to 3.0 mmol/L, measured with a finger-stick ketone meter. Urine strips are cheaper but less reliable after the first weeks.
- Diabetic ketoacidosis (DKA): ketones far higher, with the blood turning acidic. It is a medical emergency, seen mainly in type 1 diabetes or with certain diabetes medicines, and it is not the same as nutritional ketosis.
A short history of therapeutic keto
- 1921: Doctors had noticed that fasting reduced seizures. Dr. Russell Wilder of the Mayo Clinic proposed a high-fat, very-low-carbohydrate diet that copied the effects of fasting, and named it the ketogenic diet.
- 1920s–1930s: Keto became a standard treatment for children with epilepsy.
- From the late 1930s: anti-seizure drugs replaced it in most clinics.
- 1994: The story of Charlie Abrahams, a boy whose seizures stopped on keto at Johns Hopkins after medication failed, renewed interest. His family started the Charlie Foundation, and keto is now an established treatment for drug-resistant epilepsy, run by a medical team.
Therapeutic keto for epilepsy is stricter than everyday keto and always medically supervised. In the video, Dr. Dominic D'Agostino explains the difference between therapeutic and "lifestyle" keto.
How to eat keto
Typical proportions (of calories): about 70–80% fat, 15–20% protein, 5–10% carbohydrate, usually 20 to 50 grams of net carbohydrate a day. Net carbs are total carbohydrates minus fiber.
| Eat freely | Eat in moderation | Avoid |
|---|---|---|
| Meat, fish, eggs | Berries | Sugar, sweets, soft drinks, juice |
| Butter, ghee, olive oil, coconut oil, avocado | Nuts and seeds | Bread, pasta, rice, cereal |
| Leafy greens and non-starchy vegetables (broccoli, cauliflower, zucchini) | Full-fat dairy (cheese, cream, plain yogurt) | Potatoes and other starchy vegetables |
| Broth, water, unrefined salt | Dark chocolate (85% or more) | Most fruit, beans |
Clean keto and "dirty keto." Keto can be made from whole foods or from processed bars, sweeteners and fast-food burgers without buns. Arukah teaches whole-food keto, built on the whole-food foundations.
Dr. Josh Axe: *Keto Diet*
Dr. Josh Axe is a chiropractor and doctor of natural medicine and a co-founder, with Jordan Rubin, of the supplement company Ancient Nutrition. His book Keto Diet (2019) presents a 30-day plan built on clean keto:
- Whole, high-quality foods: grass-fed and pasture-raised meats, wild fish, healthy fats, plenty of non-starchy vegetables, bone broth and collagen.
- Vegetables at every meal to supply fiber, potassium and magnesium.
- No processed "keto" junk food.
- Keto cycling: after the first 30 to 60 days, he suggests most people add one or two higher-carbohydrate days a week from whole foods (sweet potatoes, fruit, squash), rather than staying in strict ketosis forever.
- The book includes several plans, including one for cancer. The course does not teach keto as a cancer treatment; cancer is treated by the client's medical team, and any diet change is discussed with them.
Keto, blood sugar and metabolic health
- Type 2 diabetes. In the video, Dr. Sarah Hallberg explains why cutting carbohydrates lowers blood sugar and insulin. In Virta Health's one-year trial, which she led, most participants lowered their HbA1c (a three-month blood sugar marker), and most who used insulin reduced or stopped it, under close medical supervision. Because blood sugar can fall quickly, medications must be adjusted by the doctor, sometimes within days.
- Weight. Keto often reduces hunger, and many people lose weight, especially at first (much of it water). Over the long run, studies find keto works about as well as other diets people can stick to.
- Where others disagree. Low-carbohydrate diets are now accepted by the American Diabetes Association as one option for diabetes. Long-term strict keto is debated: Dr. D'Agostino himself says chronic ketosis is probably not ideal for most people, which is one reason many teachers, including Dr. Axe, favor cycling.
Keto flu and electrolytes
In the first one to two weeks, many people feel "keto flu": headache, fatigue, brain fog, irritability, muscle cramps and constipation. Low insulin makes the kidneys release sodium and water, and other minerals go with them.
- Salt: more unrefined salt, or a cup of salted broth a day.
- Potassium: avocados, leafy greens and other low-carb vegetables.
- Magnesium: leafy greens, nuts, and a supplement if needed (From A to Zinc).
- Water, and easing in over a week or two rather than cutting carbohydrates overnight.
Clients with high blood pressure, heart failure or kidney disease keep to the salt and potassium limits they have been given.
Who should not do keto
- Anyone on an SGLT2 inhibitor (Jardiance, Farxiga, Invokana and similar): risk of ketoacidosis even with normal blood sugar
- Type 1 diabetes, and anyone on insulin or sulfonylureas: risk of low blood sugar and ketoacidosis
- Blood pressure medication: pressure can drop
- Pancreatitis, gallbladder disease or no gallbladder, liver failure, and rare inherited disorders of fat metabolism
- Pregnancy and breastfeeding
- Kidney disease or a history of kidney stones
- A current or past eating disorder
- Children, except on a medical team's epilepsy diet
Cholesterol. In some people, especially lean, active people, LDL cholesterol rises a great deal on keto. Clients with heart disease, high cholesterol or a family history order a lipid panel before starting and again after about three months, and compare the results. A coach does not order or interpret lab tests, but you can teach clients how to order their own tests and read their own results.
Safety notes
- Diabetes medications: SGLT2 inhibitors, insulin and sulfonylureas are reviewed by the prescriber before keto, and doses often need to come down quickly.
- Who should not do keto: see Who should not do keto.
- Ketoacidosis warning signs: nausea, vomiting, belly pain, rapid breathing, unusual tiredness or confusion, especially in someone with diabetes, mean urgent medical care.
- Cholesterol: clients with heart disease or high LDL order their own lipid panel before starting and after about three months; teach them how to order it and read it.
- Electrolytes: clients with kidney disease, heart failure or high blood pressure keep to the salt and potassium limits they have been given.
- Cancer and epilepsy: keto for these is a medical treatment, guided by the client's medical team.
No. 47Atkins Diet
Cardiologist Dr. Robert Atkins introduced his plan in Dr. Atkins' Diet Revolution (1972), and low-carb has been arguing with the bread basket ever since. It starts with a strict "induction" phase that cuts carbohydrate very low, then slowly adds carbohydrate back in stages until weight loss stops, to find each person's limit. Meat, fish, eggs, cheese, butter and low-starch vegetables are allowed freely; sugar, bread, pasta, rice and most fruit are cut at first.
Strengths
- Cuts refined sugar and white flour, which many people eat far too much of.
- Protein and fat help people feel full, so many eat less without counting calories.
- Well studied. Several trials in the 2000s compared Atkins with low-fat diets: Atkins groups often lost more weight in the first six months, but after a year the difference was usually small. Triglycerides and HDL cholesterol often improved.
Watch out for
- Long-term results depend on sticking with it, and many people drift back to old habits. The bagel knows where you live.
- Most weight loss comes from eating less overall.
- Atkins bars, shakes and sweets are processed foods, often with sweeteners, sugar alcohols and additives. A candy bar by any other name.
- Lots of processed meat and saturated fat may raise LDL cholesterol in some people.
- Fiber can run low in the early phases, leading to constipation.
Eating well within it
- Use your carbohydrate allowance on vegetables, berries, nuts and, in later phases, beans and whole grains. Spend it wisely.
- Choose fresh meat, fish and eggs over bacon, sausage and deli meats.
- Swap Atkins bars for hard-boiled eggs, cheese or a handful of nuts, no ingredient list required.
Possible supplement needs
A basic multivitamin during induction, along with magnesium and potassium.
Who should be careful
People on diabetes or blood-pressure medicines (doses may need lowering as the numbers fall), those with kidney disease, pregnant women, and people with high LDL cholesterol.
No. 48South Beach Diet
Miami cardiologist Dr. Arthur Agatston published The South Beach Diet in 2003 after looking for a plan his heart patients could actually follow. It is lower in carbohydrate than usual but focuses on "good carbs" (vegetables, beans, whole grains) and "good fats" (olive oil, nuts, fish), with less saturated fat than Atkins. It runs in phases: a strict first phase of about two weeks, a second phase that adds back whole grains and fruit, and a maintenance phase. No beach required.
Strengths
- Encourages whole foods, vegetables, lean protein, nuts and olive oil.
- More heart-friendly than early Atkins, with attention to fat quality, not just the carb count.
- Later phases allow a wide range of foods, which helps people stay with it.
Watch out for
- The strict first phase can feel hard, and early weight loss is mostly water, so hold the celebration.
- There are few long-term studies of South Beach itself.
- The brand now sells prepackaged meals, shakes and snacks. These are processed and costly, and not needed to follow the original plan, which never came in a box.
- Older versions favored low-fat dairy and "lean" products, some of which are processed.
- Most weight loss comes from eating less, and long-term results depend on sticking with it.
Eating well within it
- Cook meals from the book rather than buying packaged products.
- Choose plain yogurt, beans, oats and brown rice in the later phases.
- Use extra-virgin olive oil and nuts as your main fats.
- Keep fruit whole rather than as juice; chewing is part of the deal.
Possible supplement needs
Usually few. Vitamin D if sun is limited; omega-3 if fish rarely makes the menu.
Who should be careful
People on diabetes or blood-pressure medicines (doses may need lowering in the first phase), and anyone with a history of disordered eating.
No. 49Zone Diet
Biochemist Dr. Barry Sears introduced the Zone in his book The Zone (1995). Each meal and snack aims for about 40% of calories from carbohydrate, 30% from protein and 30% from fat. Calculator optional: food is measured in "blocks," or estimated by eye, with a third of the plate lean protein, two thirds vegetables and fruit, and a little fat such as olive oil or nuts. Sears teaches that this balance keeps hormones like insulin, and inflammation-related substances, in a healthy "zone."
Strengths
- Balanced meals with protein, produce and fat at each sitting steady energy and hunger.
- Favors vegetables, fruit, lean protein and olive oil over refined starches.
- The "eyeball" method is simple to use at home or when eating out, no measuring cups in your pocket.
Watch out for
- The hormone claims have not been confirmed in good studies. Reviews have not found that the exact 40-30-30 ratio does anything special.
- Weight loss on the Zone comes mainly from eating fewer calories, and long-term results depend on sticking with it.
- Counting blocks can feel tedious (math homework at every meal), and calories can be quite low for active people.
- Sears sells Zone-branded foods, bars and fish oil products. They are optional, whatever the packaging hints.
- Favoring very lean meats and low-fat products can push people toward processed foods.
Eating well within it
- Use the plate method rather than counting blocks.
- Pick fish, eggs, poultry and beans for protein; vegetables and whole fruit for carbohydrate.
- Use olive oil, avocado and nuts for fat.
- Cook from whole foods rather than buying Zone bars. Your kitchen can get in the zone too.
Possible supplement needs
Sears promotes fish oil. Omega-3 if you rarely eat fish.
Who should be careful
People with kidney disease, those on diabetes medicines, and athletes with high energy needs.
No. 50Dukan Diet
French doctor Pierre Dukan built this very high-protein, low-fat, low-carbohydrate plan, which became popular after his 2000 book. It has four phases, with names fit for a military campaign. "Attack" allows only lean protein foods for a few days. "Cruise" adds certain vegetables on some days. "Consolidation" slowly brings back fruit, bread, cheese and starchy foods. "Stabilization" is meant for life, with one pure-protein day a week. Oat bran is eaten daily throughout.
Strengths
- Clear rules that some people find easy to follow.
- High protein helps people feel full, and early weight loss can be quick.
- Oat bran adds soluble fiber, and refined sugar is shown the door.
Watch out for
- The British Dietetic Association has repeatedly listed it among the diets to avoid, citing its restrictive rules and lack of evidence. Not a list any diet wants to be on.
- The early phases are very low in fiber, fruit, vegetables and healthy fats. Constipation, tiredness and bad breath are common.
- Early weight loss is largely water, and many people regain weight after stopping.
- Very high protein may strain the kidneys in people with kidney disease.
- In 2014 Dukan was struck off France's medical register for practicing medicine in a commercial way. The plan itself is still widely sold.
- Most weight loss comes from eating less, and long-term results depend on sticking with it.
Eating well within it
- Choose fish, eggs, chicken and plain yogurt over processed low-fat meats.
- Move to the Cruise phase quickly so vegetables can come back from exile.
- Drink plenty of water and keep the daily oat bran for fiber.
Possible supplement needs
A basic multivitamin during the strict phases.
Who should be careful
People with kidney disease, gout or diabetes, pregnant or breastfeeding women, teens, and anyone with a history of disordered eating.
No. 51Low-Carb High-Fat (LCHF)
LCHF is a broad name for eating fewer carbohydrates and getting more energy from natural fats. It is less strict than keto, its easygoing cousin: people choose their own carbohydrate level, from moderate to very low. Popular voices include the Swedish physician-founded website Diet Doctor and South African sports scientist Tim Noakes, whose book The Real Meal Revolution spread the idea in South Africa. Typical meals are meat, fish, eggs, full-fat dairy, vegetables that grow above ground, nuts and butter or olive oil, with little sugar, bread, pasta, rice or potatoes.
Strengths
- Cuts refined sugar, white flour and most ultra-processed food.
- Trials show low-carbohydrate diets can lower blood sugar and help weight loss in people with type 2 diabetes, at least in the short term.
- Flexible, so people can find a level they can keep up, rather than one they merely survive until Friday.
Watch out for
- People on diabetes medicines, especially insulin or sulfonylureas, can get dangerous low blood sugar when carbohydrates drop. Their medicines usually need lowering before carbohydrates drop.
- Long-term studies comparing LCHF with other healthy diets show mixed results after a year or two.
- LDL cholesterol rises in some people, especially with lots of butter and cream.
- Fiber can run low if vegetables are skimped.
- Most weight loss comes from eating less, and results depend on sticking with it.
Eating well within it
- Fill your plate with leafy and above-ground vegetables.
- Use olive oil, avocados, nuts and fish as main fats, with butter and cream in moderation, not by the tub.
- If your carbohydrate limit allows, include berries, beans or lentils.
Possible supplement needs
Usually few. Magnesium and vitamin D.
Who should be careful
Anyone on diabetes or blood-pressure medicines, pregnant women, people with high LDL cholesterol, and those with kidney disease.
No. 52Bulletproof Diet
Entrepreneur Dave Asprey launched this approach with The Bulletproof Diet (2014). It is mostly paleo-style: grass-fed meat, wild fish, eggs, vegetables, butter and MCT oil, with weekly higher-carbohydrate days. Asprey teaches avoiding "anti-nutrients" such as lectins, phytates and oxalates, and molds in some foods. His signature is Bulletproof coffee, blended with butter or ghee and MCT oil, often drunk in place of breakfast. Yes, butter in your coffee.
Strengths
- Avoids sugar, refined grains, refined seed oils and processed food.
- Emphasizes vegetables, quality meat and fish, and good sleep.
- Some people enjoy the steady energy of a high-fat morning and skipping breakfast.
Watch out for
- Bulletproof coffee replaces a meal with mostly fat. You miss the protein, fiber, vitamins and minerals a real breakfast would supply, however much butter is in the mug.
- A daily cup can add a lot of saturated fat, which raises LDL cholesterol in some people.
- The "anti-nutrient" claims go well beyond the evidence. Beans, whole grains and many vegetables are linked to good health, and cooking reduces most of these compounds.
- Asprey's company sells coffee, MCT oil, bars and supplements, and many recommendations point toward his products. Funny how that works.
- There are no trials of the diet itself. Most weight loss comes from eating less and sticking with it.
Eating well within it
- Enjoy Bulletproof coffee occasionally, then eat a proper meal with eggs and vegetables.
- Use ordinary coffee, butter or coconut oil; branded products are not required, whatever the label says.
- Eat a wide variety of vegetables, cooked if raw ones bother you.
Possible supplement needs
Usually few. Vitamin D if sun is limited.
Who should be careful
People with high LDL cholesterol or heart disease, those sensitive to caffeine, and anyone with gallbladder or digestive problems with high-fat meals.