Life in the 'fast' lane

A new diet trend called “intermittent fasting” was recently featured on the Today Show. The diet is an eating pattern that alternates between fasting and eating, and focuses more on when you eat rather than what you eat.

The most popular plan is fasting for 16 hours, followed by an eight-hour eating window, typically between 8 am and 2 pm. Another method is alternating 500-calorie days with eating normally, and fasting for two days (not in a row) within a week.

While it hasn’t been scientifically proven, a study in The Journal of Obesity reports that intermittent fasting works by curbing appetite rather than by burning more calories. The report states that this eating method decreases ghrelin, the hunger hormone, while increasing leptin, the satiety hormone.

The same study shows that fasting prompts obese people to dip into their fat reserves, causing them to burn more fat.

“I have seen success with intermittent fasting for some of my patients with a BMI of 40 or higher, which is considered obese,” said Jillian McMullen, a registered dietitian at the Baptist Center for Bariatrics. “It can also help jump-start weight loss if a patient reaches a plateau after having weight-loss surgery.”

McMullen said it’s important to eat healthy during the eating window and not to overeat. “You can’t go crazy during the non-fasting hours. You still have to be controlled and eat sensibly or it will defeat the purpose,” she said.

For people who want to lose a moderate amount of weight, say 10-20 pounds, intermittent fasting may help for a short period of time.

“As with any type of fad diet,” said Patricia Calhoun, MD, a family care physician with Baptist Primary Care, “the concern is for long-term sustainability. There are a few studies that show that intermittent fasting is probably equal to other healthy calorie-restricted eating plans—but not tremendously better.”

One tip for curbing feelings of hunger while fasting includes eating high-fiber foods like nuts, beans, fruits and vegetables, along with high-protein foods like meat, fish, tofu or nuts, during the eating window. Drinking 64 or more ounces of water a day may also be helpful.

Always check with your doctor before starting a new diet. “Some people are not good candidates for this type of diet,” said Dr. Calhoun. “This includes pregnant women, lactating women, those with certain eating disorders, and diabetics who require strict glucose monitoring. Always check with your physician before beginning any significantly rigorous diet or exercise program.”

If you are looking for a primary care physician, call 904-202-4YOU (4968) or visit Baptist Primary Care.