A new study from the University of Southern California shows that restricting calories just five days a month for three months:
• helped people lose weight,
• reduced a number of risk factors for cancer, diabetes and heart attacks, and
• improved markers for living a longer life and tests for immune function
(Cell Metabolism, published online June 18, 2015). The study author, Valter D. Longo, says that “the research demonstrates the first anti-aging, healthspan-promoting intervention that doctors could feasibly recommend for patients.”
The Study
Thirty-seven men and women participated in the three-month study. For 25 days in each month, they all ate their normal diets. For the other five days each month, 19 of the subjects restricted calories to between one third and one half of their normal intake (the fasting group), while the other 18 continued to eat their regular diet and did not restrict calories (the control group). The fasting group was fed 1,090 calories on the first “fast” day and 725 calories per day for the other four “fast days”. Their food on these days consisted of vegetable soups and chamomile tea.
How Might Intermittent “Fasting” Prolong Life?
Nobody really knows whether intermittent low-calorie diets help to promote weight loss and to prevent disease, but after three months of this regimen, the fasting group had a reduction in risk factors linked to aging, heart attacks, diabetes and cancer, including lowered blood glucose, reduced markers of inflammation and weight loss.
In similar studies, humans and animals have had a marked lowering of a hormone called Insulin-Like Growth Factor-1 (IGF-1), high levels of which increase risk for cancer and premature death. Intermittent low-calorie diets have been shown to extend the lives of yeast and mice. Mice in an intermittent fasting program had less belly fat which helped protect them from developing diabetes, more brain nerve growth promoting memory, and lower IGF-1 levels. Other studies published this year show that periodic fasting helps to prevent diabetes in those who are at high risk.
Weigh Yourself Every Day
Another study found that weighing yourself daily is one of the most effective ways to track your weight and do something immediately to help you lose weight or prevent weight gain (Journal of Obesity, June 2015). Weigh yourself at the same time of day each morning. If you are trying to lose weight, use your scales to monitor your progress. If you are trying to prevent weight gain, add a “fast” day whenever your scales show that you have gained a pound or more.
A report from the National Health and Nutrition Examination Survey shows that today North Americans are fatter than ever before. More than 75 percent of men and 67 percent of women over age 25 are overweight or obese (JAMA Internal Medicine, June 22, 2015). Many studies show that being even slightly overweight appears to shorten lives. Most weight loss programs fail to help people keep weight off after they have lost it. Fasting can cause hunger which is painful, so most people will not do it. I have found that a modified program of intermittent fasting with snacking is easy and relatively painless. I believe that future research will show that intermittent fasting helps to control weight and to prevent the many diseases that are linked to excess weight.
