Lifestyle+ — 7

1.6 g

Linoleic Acid

14 g

Dietary Cholesterol

As low as possible while consuming a nutritionally adequate diet

Total Water

3.7 L (about 16 cups)

(https://www.nal.usda.gov/human-nutrition-and-food-safety/dri-calculator)

Some doctors, like Peter Attia, have advocated for intake of one gram per body weight in pounds (not per kg), which has not been substantiated by evidence. Indeed, a study of high-protein diets in people and mice warned of the danger of promoting atherosclerosis through an increase in plasma leucine, an essential amino acid building block of proteins, and impaired cellular waste disposal (autophagy). The gut microbiome of people who consume a high-protein diet (more than 1.5 g/kg) has been shown to produce pro-inflammatory metabolites. While increasing your diet up to 1.2 gram/kilograms of protein is reasonable, it’s the leucine-rich animal proteins that should be avoided. High-protein diets are intended to reduce the risk of sarcopenia—age-related loss of muscle mass and strength—which has been unequivocally demonstrated (in many studies, such as quantifying handgrip) is a well-established risk factor for reduced health span. We don’t know that increasing protein in the diet with age titrates or negates that risk, which would require a randomized trial with multiyear follow-up that will likely never get done. (That’s because randomized trials of diets are extremely hard to do at scale; also, it’s difficult to rely on participants’ long-term adherence and difficult to obtain financial support.) Furthermore, there’s no information on food labels about the specific amino acids (nine of the twenty) in our diet that we require because we can’t synthesize them—such as leucine, lysine, and methionine. Note that the recommendations above break down fats but not proteins. The hard truth is that we could be doing so much more to upgrade our knowledge of dietary protein intake that’s not being done.

Like sugar, there is a dedicated gut-brain reward circuit for fat intake conveyed through the vagus nerve. Separately, the fat circuit encourages more caloric intake, but it is synergistic with the sugar reward circuit for promoting dopamine release and overeating. Single-cell studies identified that the vagal neurons involved in the circuit, when silenced, abolished fat intake preference. Just as we’ve seen with salt, carbs, and proteins, there’s no shortage of uncertainty. Take dairy products, a source of saturated fat, for example. The guidance to steer us to low-fat milk and yogurt dates back to 1980 and has never been updated. A 2018 report in more than 130,000 people from twenty-one countries followed for nine years found that consumption of two or more servings of dairy daily was associated with 22 percent less cardiovascular disease and 17 percent less all-cause mortality, with a greater reduction in those with greater whole fat dairy consumption. That same year a report from more than sixty thousand adults tracked for an average of nine years found a 29 percent reduction in type 2 diabetes related to greater dairy intake. Particularly yogurt (without sweeteners) and cheese (harder like cheddar or parmesan for slower absorption) have been most associated with better outcomes, which coincides with some current recommendations for three servings of dairy per day, with one or two made up of yogurt or cheese.