Intermittent Fasting — Dr. Laughlin Blog — Primary Care Physician in Tulsa, OK

Intermittent fasting (IF) is a new diet and fitness trend. IF is an eating pattern that cycles between periods of fasting and eating. Human studies have shown that IF is safe and effective, though not necessarily more effective than other diets. And a growing body of research has shown that the timing of the fast is the key to success in sustainable weight loss and diabetes prevention.

Diet experts, including those who advocate fasting, are clear in their recommendations that we should eat more fruits and vegetables, fiber, healthy protein and fats, and that we should limit sugar, refined grains, and processed foods. And that we should avoid snacking.

The food we eat is digested and ends up in our blood stream. Carbohydrates and refined grains are quickly broken down into sugar, which our cells need for energy. Excess sugar is stored as fat. Sugar only enters the fat cells in the presence of insulin, a hormone made in the pancreas. Between meals, so long as we don’t snack, insulin levels drop and our fat cells release stored sugar that is then used for energy. We lose weight when our insulin levels go down. IF works because our insulin levels drop far enough and for long enough that we burn off our fat.

Common intermittent fasting methods involve daily 16-hour fasts or fasting for 24 hours, twice per week. Fasting was the norm throughout most of our evolution, since hunter-gatherers often spent hours or even days without anything to eat. As a result, humans evolved to be able to function without food for extended periods of time. Fasting is therefore more natural for us than eating 3- 4 times per day.

The most popular methods of IF are:

The 16/8 method, which usually includes skipping breakfast and restricting daily eating to an eight-hour period, such as 1-9 p.m.
Eat-Stop-Eat, in which you fast for 24 hours, once or twice a week on non-consecutive days.
The 5:2 diet, in which you eat only 500-600 calories per day on two non-consecutive days and eat normally the other 5 days.

The health benefits of IF include weight loss, reduced insulin resistance (which should protect against diabetes), reduced inflammation, improved heart health through the lowering of “bad” LDL cholesterol and triglycerides, and possibly a slow-down in the aging process.

Before trying IF you should consult your doctor if you have diabetes or other problems with blood sugar regulation, are underweight, take medications, have a history of eating disorders, are a woman trying to conceive, are a woman with a history of abnormal menstrual periods and/or are a woman who is pregnant or breastfeeding.

Overall, IF has an outstanding safety profile, and its most common side effect is hunger. IF is not for everyone, but if you feel good when fasting and find it a sustainable way of eating, it can be a very powerful way to lose weight and improve your health.