Eating Patterns

More and more interest and research on health effects of eating timing has popped up in the scientific literature recently. A previous blog discussed the value of intermittent fasting, concluding that longevity and freedom from chronic disease were greatly improved by periods of fasting which can be as simple as not eating for a consecutive 12 to 16 hours daily.

The brain has a master clock which governs sleeping and waking dependent on exposure to bright light. Every other organ has a similar clock: the pancreas produces less insulin at night; the human gut and its microbiome also have a rhythm with the genes of the gut itself and its bacteria switching on and off at the same time.

People who interfere with this normal circadian rhythm by staying up too late have increases in weight, blood pressure and blood sugar. Night shift workers typically have poorer health.

More extreme periods of daily fasting have surprisingly powerful effects. Prediabetic men who are limited to only eating in a six hour window each day have improvement in blood pressure, less hunger, and less insulin secretion compared to those allowed to eat over a 12 hour window. If laboratory animals are given a poor quality diet with around the clock food access they get fat and sick. The same diet and food quantity limited to an eight hour window does not cause obesity or disease.

Significant health improvements, especially in weight and blood sugar, are seen if most calories are consumed early rather than late in the day.

A recent book, The Circadian Code, by Dr. Satchin Panda of the Salk Institute reviews his and others' research on eating patterns.