Alternate-Day Fasting Shows Promise For Obese Dieters
Restricting daily calorie intake is a common plan to help obese and overweight people slim down to healthier weights. But the regime requires a daily 15 to 40 percent calorie reduction, which makes sticking to the diet hard for many.
University of Illinois at Chicago researchers have found that a modified version of a plan called “alternate-day fasting” may be easier to abide and has the added bonus of improving cardio health. The findings appear in the November 1 issue of The American Journal of Clinical Nutrition.
“This diet has been around about 20 years, but its effect on weight loss hadn’t really been studied,” said Krista Varady, assistant professor of kinesiology and nutrition, who led the UIC research team.
The 10-week trial studied 16 clinically obese people — 12 women and four men — between the ages of 35 and 65 who all weighed more than 210 pounds, had kept their weight stable for the previous three months, and had body mass indexes of between 30 and 39.9. None was diabetic, had a history of cardiovascular disease, was taking weight-loss or lipid- or glucose-lowering medications, or smoked.
The study was divided into three phases:
The first two weeks, participants ate and exercised normally.
Between weeks three and six, participants ate normal meals one day then would fast the next. On fast days, participants ate the equivalent of a three-course lunch prepared by UIC’s Human Nutritional Research Center. The meal provided between 20 and 25 percent of daily energy needs. Read more
The Correct Combination Of Proteins Is Decisive For Healthy Aging, Not Reducing The Calories In Our Diet
A new study of the Max Planck Institute for Biology of Ageing could help to understand the positive effect of dietary restriction on healthy ageing. Previous evidence from different organisms (fruit flies and mice) have shown that dietary restriction increases longevity, but with a potential negative side effect of diminished fertility. So the female fruit fly reproduces less frequently with a reduced litter size on a low calorie diet, but its reproductive span lasts longer. This is the result of an evolutionary trait, as scientists believe: essential nutrients are diverted towards survival instead of reproduction. (Nature, December 3, 2009)
Researchers from the newly founded Max Planck Institute for Biology of Ageing in Cologne have studied whether health benefit stem from a reduction in specific nutrients or calorie intake in general by manipulating the diet of female fruit flies. The fruit flies were fed a diet of yeast, sugar and water, but with differing amounts of key nutrients, such as vitamins, lipids and amino acids. The scientists were able to show that longevity and fertility are affected by a combination of the type and amount of amino acids; whilst varying the amount of the other nutrients had little or no effect. Furthermore, the researchers found out in previous studies that levels of a particular amino acid – methionine – were crucial to increasing lifespan without decreasing fertility. By carefully manipulating the balance of amino acids, both lifespan and fertility were maximised. For the first time, this indicates that it is possible to extend lifespan without wholesale dietary restriction and without lowering reproductive capacity. Read more