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Short Summary
Main recommendation: Combine a low-carbohydrate, high-fat ketogenic diet with intermittent fasting, using the keto diet to shift the body toward burning fat and fasting to limit when you eat. Dr. Jason Fung presents this pairing as the most effective approach in his review of the top three most-Googled diets of 2020, using the case of Dave, who reversed his type 2 diabetes with it.
Key Points
- The paleo diet (also called the caveman, Stone Age, or hunter-gatherer diet) emphasizes meat, seafood, vegetables, and roots while excluding grains, dairy, sugar, and salt; Dr. Fung cites a 2019 review finding an average loss of 3.7 pounds versus a standard diet, plus lower blood triglycerides and blood pressure.
- Paleo's popularity peaked around 2013 to 2014 and has declined since, partly because companies commercialized it with paleo cookies, crackers, bars, and protein, and partly because the diet is restrictive and historically imprecise.
- Intermittent fasting is not a diet about what to eat but about when to eat, so it can be combined with any diet; its Google interest has risen steadily while paleo's has fallen.
- The keto diet is the most-searched trend of 2020, and Dr. Fung explains it works by the liver producing ketones from fat, which feed the brain when glucose is restricted.
- Dr. Fung says keto was used for epilepsy as early as 500 BC, fell out of use in the 1920s with new medications, and was revived in the mid-1990s after a Hollywood producer's son's seizures stopped on the diet.
Details Worth Noting
- Concrete instructions:
- Keto: keep net carbohydrates (total carbohydrates minus fiber) under about 20 grams per day to reach ketosis; the video contrasts this with a standard low-carb definition of under 50 grams and a typical diet of 200 to 300 grams.
- Keto food choices: avoid starches such as potatoes, rice, grains, and flour-based foods, and avoid fruit; eat meat, above-ground vegetables, eggs, and fish, with an emphasis on real foods.
- Keto eating pattern: eat only when hungry rather than all the time, so the body keeps burning body fat.
- Dr. Fung notes ketosis can be checked with ketones measured in blood, a breath test, or urine.
- Intermittent fasting: set aside fixed periods without eating; Dave started with 36-hour fasts and mixed in 42-hour and 72-hour fasts.
- Managing fasting hunger: expect hunger, recognize that it rises and then passes like a wave, and embrace it rather than eating.
- Dr. Fung recounts that Dave was 35 when diagnosed with type 2 diabetes at 334 pounds; keto first dropped his weight by 25 pounds and lowered his A1c to a non-diabetic level, but reintroducing small amounts of carbohydrate made his blood sugar spike again until fasting was added.
- The video describes the keto diet as using moderate protein and a higher share of dietary fat than earlier low-carb diets, and this higher fat intake was an unexpected source of weight loss.
- The video presents this information as Dr. Fung's review and does not offer it as professional medical advice.
Bottom Line
Dr. Fung's view is that among the 2020 diet trends reviewed, keto paired with intermittent fasting is a strong tool for weight loss and blood sugar control, while paleo's decline reflects commercialization and restrictiveness rather than lack of benefit.
