Eating by the clock
A fasting regimen on a 24-hour cycle (like 16:8 or a 14:10 breakdown) allows you to align your fasting with your natural sleep/wake cycles. Sears says this is important because circadian rhythms regulate the processing of nutrients. For example, insulin is most effective in the morning and midday; in the evening and overnight, you have higher levels of hormones like melatonin that interfere with insulin action. “If you eat a snack at night, the insulin you secrete to process it isn’t going to function as well as if you ate that same food for breakfast,” she says. Since your insulin response—which is responsible for shuttling sugar from your bloodstream into your cells—is dampened, your blood sugar will stay higher for longer, she explains. If that happens repeatedly, it can increase your risk for cardiovascular disease, type 2 diabetes, and cancer. By eating breakfast a touch later (say, 8 a.m.) and moving dinner a bit earlier (finishing around 6 p.m.), you can align your food intake with your circadian rhythm and still get that prolonged overnight fast without too much extra effort.