Pros and Cons: Potential downsides
Keep in mind that the Bulletproof Diet has several drawbacks.
Not rooted in science
The Bulletproof Diet claims to be based on solid scientific evidence, but the findings it relies upon are of poor quality and not applicable to most people. For instance, Asprey cites shoddy data claiming that cereal grains contribute to nutritional deficiencies and that the fiber in brown rice prevents protein digestion. However, cereal grains are often fortified with many important nutrients, and their consumption actually increases — not decreases — your intake of important nutrients. And while it’s known that fiber from plant foods like rice decreases the digestibility of some nutrients, the effect is rather small and of no concern as long as you’re consuming a well-balanced diet. Asprey also provides oversimplified views of nutrition and human physiology, suggesting that people shouldn’t regularly consume fruit since it contains sugar or that all dairy — except ghee — promotes inflammation and disease. In fact, fruit consumption is associated with weight loss, and dairy products have been shown to have anti-inflammatory effects.

Can be expensive
The Bulletproof Diet can get expensive. Asprey recommends organic produce and grass-fed meats, stating that they’re more nutritious and contain less pesticide residue than their conventional counterparts. However, because these items are much more expensive than their conventional parts, not everyone may be able to afford them. While organically grown produce tends to have lower pesticide residue and may contain greater levels of certain minerals and antioxidants than conventionally grown produce, the differences are probably insignificant to have any real health benefit. The diet also recommends frozen or fresh vegetables over the often more affordable and convenient canned vegetables, despite there being no real health benefit.
Requires special products
The Bulletproof line of branded products makes this diet even more expensive. Many of the items in Asprey’s food spectrum that rank as Bulletproof are his own branded products. It’s highly dubious for any person or company to claim that buying their expensive products will make your diet more successful.
Can lead to disordered eating
Asprey’s continual classification of food as “toxic” or “Bulletproof” may lead people to form an unhealthy relationship with food.Consequently, this can lead to an unhealthy obsession with eating so-called healthy foods, termed orthorexia Nervosa. One study found that following a strict, all-or-nothing approach to dieting was associated with overeating and weight gain. Another study suggested that strict dieting was associated with the symptoms of an eating disorder and anxiety.
The bottom line
The Bulletproof Diet combines a cyclical ketogenic diet with intermittent fasting. It claims to help you lose up to a pound (0.45 kg) per day while boosting energy and focus. Yet, evidence is lacking. It may be beneficial for appetite control, but some may find it hard to follow. Keep in mind that the diet promotes inaccurate health claims and mandates the purchasing of branded products. Overall, you may be better off following proven dietary tips that won’t be as expensive and will promote a healthy relationship with food.
Journal Entry – “Daily Thoughts”
Do you need three meals a day? How did your body react to skipping breakfast? How do you feel? Would you maintain any of the last couple of weeks as a regular part of your routine?