Low-calorie diet helps lose weight, boosts immunity

Washington, Apr 30 (ANI): People who follow a low-calorie diet or a very low-calorie diet not only lose weight, but also significantly enhance their immune response, concludes a new study.

The study may be the first to demonstrate the interaction between calorie restriction and immune markers among humans.

The lead researcher, Simin Nikbin Meydani, is director of the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, Mass., and also of the HNRCA”s Nutritional Immunology Laboratory.

The study is part of the “Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy” trial conducted at the HNRCA. As people age, their immune response generally declines. Calorie restriction has been shown to boost these immune responses in animal models.

In the study, 46 overweight (but not obese) men and women aged 20 to 40 years were required to consume either a 30-percent or 10-percent calorie-restricted diet for six months.

Prior to being randomly assigned to one of the two groups, each volunteer participated in an initial 6-week period during which measures of all baseline study outcomes were obtained. All food was provided to participants.

For the study, the researchers looked at specific biologic markers. A skin test used called DTH (delayed-type hypersensitivity) is a measure of immune response at the whole body level.

The researchers also examined effects of calorie restriction on function of T-cells–a major type of white blood cell–and other factors on the volunteer”s immune system.

DTH and T-cell response indicate the strength of cell-mediated immunity. One positive was that DTH and T-cell proliferative response were significantly increased in both calorie-restrained groups.

These results show for the first time that short-term calorie restriction for six months in humans improves the function of T-cells. (ANI)

Consuming low calorie diet leads to ‘longer, healthier life’

Washington, July 10 (ANI): Substantially cutting calories from the diet could slow the ageing process and increase life expectancy, according to a decades-long study of monkeys.

Researchers at the University of Wisconsin-Madison, the Wisconsin National Primate Research Center and the William S. Middleton Memorial Veterans Hospital have found that a nutritious but reduced-calorie diet blunts aging and significantly delays the onset of such age-related disorders as cancer, diabetes, cardiovascular disease and brain atrophy.

“We have been able to show that caloric restriction can slow the aging process in a primate species,” says Richard Weindruch, a professor of medicine in the UW-Madison School of Medicine and Public Health who leads the National Institute on Aging-funded study. “We observed that caloric restriction reduced the risk of developing an age-related disease by a factor of three and increased survival.”

During the 20-year course of the study, half of the animals permitted to eat freely have survived, while 80 percent of the monkeys given the same diet, but with 30 percent fewer calories, are still alive.

Begun in 1989 with a cohort of 30 monkeys to chart the health effects of the reduced-calorie diet, the study expanded in 1994 with the addition of 46 more rhesus macaques. All of the animals in the study were enrolled as adults at ages ranging from 7 to 14 years.

Today, 33 animals remain in the study. Of those, 13 are given free rein at the dinner table, and 20 are on a calorie-restricted diet. Rhesus macaques have an average life span of about 27 years in captivity. The oldest animal currently in the study is 29 years.

Weindruch notes that in terms of overall animal health, the restricted diet leads to longer lifespan and improved quality of life in old age.

“There is a major effect of caloric restriction in increasing survival if you look at deaths due to the diseases of aging,” he said.

The study has been published in the journal Science. (ANI)

Vibration plate machines may help weight loss, trim abdominal fat

Washington, May 9 (ANI): Vibration plate exercise machines, if used properly, may help you lose weight and trim the particularly harmful belly fat between the organs, claims a new study.

In a study presented at the European Congress on Obesity, scientists found that overweight or obese people who regularly used the equipment in combination with a calorie restricted diet were more successful at long-term weight loss and shedding the fat around their abdominal organs than those who combined dieting with a more conventional fitness routine.

“These machines are increasingly found in gyms across the industrialized world and have gathered a devoted following in some places, but there has not been any evidence that they help people lose weight. Our study, the first to investigate the effects of vibration in obese people, indicates it’s a promising approach. It looks like these machines could be a useful addition to a weight control package,” said the study’s leader, Dirk Vissers, a physiotherapist at the Artesis University College and the University of Antwerp in Belgium.

To reach the conclusion, Vissers and his colleagues studied the effects of the Power Plate in 61 overweight or obese people – mostly women – for a year. The intervention lasted six months, after which the scientists advised all the volunteers to do the best they could with a healthy diet and exercise regime on their own for another six months. Body measurements, including CT scans of abdominal fat, were taken at the beginning of the study and after three, six and 12 months.

The researchers divided the volunteers into four groups. One group was prescribed an individually calculated calorie restricted diet. Dietician visits were scheduled every fortnight for the first three months and every month for the second three months. The dieters were asked not to engage in any exercise for the duration of the six-month intervention.

A second group received the same diet intervention, with the addition of a conventional fitness regime. They attended supervised exercise classes twice a week for an hour and were urged to exercise on their own a third time each week. The sessions included group cycling, swimming, running, step aerobics and some general muscle strengthening exercises.

A third group got the diet intervention plus supervised vibration plate training instead of conventional exercise. They were asked not to do any aerobic exercise during the six-month intervention phase. The physiotherapists gradually increased the speed and intensity of the machine each week, as well as the variety and duration of the exercises from 30 seconds for each of 10 exercises to 60 seconds for each of 22 exercises, such as squats, lunges, calf raises, push-ups and abdominal crunches.

The average time spent on the machine was 11.9 minutes per session in the first three months and 14.2 minutes in the second three months.

A fourth group got no intervention. There were no significant differences between the groups in obesity and abdominal, or visceral, fat at the start of the study.

“Over the year, only the conventional fitness and vibration groups managed to maintain a 5 percent weight loss, which is what is considered enough to improve health,” Vissers said.

During the first six months, the diet only group lost about 6 percent of their initial body weight, but could not maintain a 5 percent weight loss in the subsequent six months. The group that got diet plus conventional fitness lost about 7 percent of their initial body weight in the first six months, but they didn’t put much of it back on and by the end of the study, they had managed to keep off a 6.9 percent loss.

The vibration group lost 11 percent of their body weight during the intervention phase and by the end of the follow-up period they had maintained a 10.5 percent loss. The control group gained about 1.5 percent of their original body weight.

The vibration group lost 47.8 square centimetres of visceral fat during the first six months and still had a loss of 47.7 square centimetres at 12 months. Visceral fat shrank by 17.6 square centimetres in the conventional fitness group in the first six months, but by the end of the year, it was only 1.6 square centimetres less than at the beginning. The diet group had a visceral fat loss of 24.3 square centimetres after six months and 7.5 square centimetres after a year. (ANI)