According to researchers reducing calories may very well mean you have a longer life.
Scientists already have evidence which suggest that prolonged calorie restriction increases maximum life span in rodents and researchers at Louisiana State University in Baton Rouge were interested to see whether prolonged calorie restriction affected the biomarkers of longevity in humans.
Dr. Eric Ravussin, and his team enrolled 48 healthy overweight but not obese, men and women in a 6-month trial in order to look at the effects of calorie reduction.
The men and women were assigned to one of four groups: a control group, which followed a normal diet; a calorie restriction group, which received 25 percent less calories than the daily requirement; a third group, which exercised and reduced calorie intakes (12.5 percent calorie restriction and 12.5 percent increase in energy expenditure); or a group that received a very low calorie diet, starting with 890 kcal a day and then increased to maintain a 15 percent weight loss.
The researchers found that after 6 months, while patients in the control group lost about 1 percent of their weight, both calorie restriction groups lost approximately 10 percent of their weight with or without exercise, while those on the very low-calorie diet lost nearly 14 percent of their weight.
The researchers also found lower blood levels of insulin after fasting and a lower body temperature in all participants who undertook a restricted calorie regimen.
Body temperature and blood insulin levels are considered markers of longevity and it has been shown both in animals and humans that those with lower body temperature tend to live longer, as do those with lower fasting insulin levels.
It was also found that less DNA damage seemed to occur in patients with lower calorie intakes.
The researchers say the findings suggest that prolonged calorie restriction in humans supports the theory that metabolic rate is reduced beyond the level expected from reduced metabolic body mass.
But they believe studies of longer duration are needed to determine if calorie restriction attenuates the aging process in humans.