An article published recently in the journal The Lancet Public Health by Dr. Seidelmann looked at the macronutrient percent intake over time and compared it with all cause mortality.
“We studied 15,428 adults aged 45-64 years, in four US communities, who completed a dietary questionnaire at enrollment in the Atherosclerosis Risk in Communities (ARIC) study (between 1987 and 1989), and who did not report extreme caloric intake (<600 kcal or >4200 kcal per day for men and <500 kcal or >3600 kcal per day for women). The primary outcome was all-cause mortality.”
The results were as follows: “Both high and low percentages of carbohydrate diets were associated with increased mortality, with minimal risk observed at 50-55 percent carbohydrate intake. Low carbohydrate dietary patterns favoring animal-derived protein and fat sources, from sources such as lamb, beef, pork, and chicken, were associated with higher mortality, whereas those that favored plant-derived protein and fat intake, from sources such as vegetables, nuts, peanut butter, and whole-grain breads, were associated with lower mortality, suggesting that the source of food notably modifies the association between carbohydrate intake and mortality.”
This study reinforces the Blue Zones data and many studies that look at macronutrient intake. I truly believe that the key to longevity is a healthy and diverse microbiome which is developed primarily through the consumption of fruits, vegetables and legumes.
If 55 percent of your intake should be carbohydrate and this is the pattern with the best health outcomes, what does that look like? If you are a mother-to-be or nursing mother, look at a hypothetical plate at every meal, make half of the plate plant based whole food carbs and the rest fat and protein, aiming for plant proteins at most meals. The non-digestible fibers in the plants will directly feed your gut microbiome which will increase its diversity and performance for you.
This study reinforces my worry about fad diets like a chronic ketogenic diet. The odds that chronic nutritional ketosis is good over the long haul is diminishingly unlikely. It does not contain the fibers necessary for a healthy microbiome to flourish

Fiber, fiber and then some fiber,
Dr. M

Dr. Chris Magryta is a physician at Salisbury Pediatric Associates. Contact him at newsletter@salisburypediatrics.com