Studies Offer Practical Weight-Loss Advice

Two studies issued this week provide chronic dieters with a couple of easy tips to aid their weight-loss quest. A light lunch and some low-fat dairy seems to help.

Researchers are Cornell, writing in the October issue of Appetite, say eating a light lunch makes it easier to shed pounds. They say study participants who ate portion-controlled lunches did not compensate by eating more calories later in the day, leading researchers to believe the human body does not possess the mechanisms necessary to notice a small drop in energy intake.

"Making small reductions in energy intake to compensate for the increasing number of calories available in our food environment may help prevent further weight gain, and one way of doing this could be to consume portion-controlled lunches a few times a week," said doctoral student Carly Pacanowski, who co-authored the study with David Levitsky, Cornell professor of nutritional sciences and of psychology.

The study closely monitored the food intake of 17 volunteers who ate whatever they wanted from a buffet for one week. For the next two weeks, half the group selected their lunch by choosing from one of six commercially available, portion-controlled foods, such as Chef Boyardee Pasta or Campbell's Soup at Hand, but could eat as much as they wished at other meals or snacks. For the final two weeks, the other half of volunteers followed the same regimen.

While eating portion-controlled lunches, each participant consumed 250 fewer calories per day and lost, on average, 1.1 pounds.

"The results confirm that humans do not regulate energy intake with any precision. Over a year, such a regimen would result in losing at least 25 pounds," said Levitsky, who adds the study demonstrates one simple, low-cost way to consume fewer calories.

Dairy's effect on belly fat

What you eat, of course, can also make a difference. Another study suggests a higher-protein, lower-carbohydrate energy-restricted diet has a major positive impact on body composition, trimming belly fat and increasing lean muscle, particularly when the proteins come from dairy products.

The study, published in the September issue of the Journal of Nutrition, compared three groups of overweight and obese, but otherwise healthy, premenopausal women. Each consumed either low, medium or high amounts of dairy foods coupled with higher or lower amounts of protein and carbohydrates.

The women exercised seven days per week for four months, a routine that included five days of aerobic exercise and two days of circuit weightlifting.

According to the researchers, there were identical total weight losses among the groups, but the higher-protein, high-dairy group experienced greater whole-body fat and abdomen fat losses, greater lean mass gains and greater increases in strength.

The tissue composition, exclusively fat, of the weight the women lost has profound implications for longer-term health, say the researchers.

"One hundred per cent of the weight lost in the higher-protein, high-dairy group was fat. And the participants gained muscle mass, which is a major change in body composition," said Andrea Josse, lead author of the study and a graduate student in the Department of Kinesiology at McMaster University. "The preservation or even gain of muscle is very important for maintaining metabolic rate and preventing weight regain, which can be major problem for many seeking to lose weight."