MONDAY, June 16, 2008 (HealthDay News) -- Boosting the flavor of your food with calorie-free seasonings and sweeteners may help you feel fuller faster and decrease the amount you eat, according to a U.S. study that suggests this may be a new way to help people lose weight.
The study of "tastants" -- substances that can stimulate the sense of taste -- included 2,436 overweight or obese people who were asked to sprinkle a variety of savory or sweet crystals on their food before eating their meals. They used the salt-free savory crystals on salty foods and used the sugar-free sweet crystals on sweet or neutral-tasting foods. The participants didn't know what the flavors of the crystals were, other than salty or sweet. The hidden flavors of the savory tastants were cheddar cheese, onion, horseradish, ranch dressing, taco, and parmesan. The flavors of the sweet tastants were cocoa, spearmint, banana, strawberry, raspberry and malt.
A control group of 100 people didn't use tastants. Both groups continued their normal diet and exercise habits during the study.
At the start of the study, the treatment group had an average weight of 208 pounds and an average body mass index (BMI) of 34, which is considered obese. After six months of using the tastants, the 1,436 people in the treatment group who completed the study lost an average of 30.5 pounds, and their BMI decreased by an average of five points.
In the control group, the average weight loss was two pounds, and the average BMI decrease was 0.3.
The findings were to be presented at the Endocrine Society's annual meeting in San Francisco.
The people in the treatment group may have lost more weight than those in the control group, because the tastants made them feel full faster, and they ate less, suggested study author Dr. Alan Hirsh, founder and neurologic director of the Smell & Taste Treatment and Research Foundation in Chicago.
Another possibility is that the tastants improved the flavor of bland but healthy foods such as tofu and some vegetables, resulting in healthier eating habits.
Tastants aren't commercially available, but people can use techniques of enhancing their senses of smell and taste to help them lose weight, Hirsch said.
"Sniff your food before you eat it. Chew it a lot. Choose low-calorie foods and season them," he said.
In another study to be presented at the Endocrine Society meeting, researchers found that three months of aerobic exercise decreased body fat and calorie intake in overweight and obese people. These changes were linked to increased levels of a protein called brain-derived neurotrophic factor (BDNF), said the team from the University of Chile Clinical Hospital in Santiago.
BDNF's main role is to promote the growth and survival of nerve cells, but recent research has shown that BDNF also is related to obesity and metabolism.
This study included 15 overweight or obese men and women, ages 26 to 51, who did a three-month program of aerobic exercise on a treadmill and bicycle. They were told they could continue to eat their usual number of calories.
At the end of the study, the participants had decreased BMI, waist circumference, and blood pressure, and reported consuming fewer calories than at the start of the study. They also had increased levels of BDNF. The higher the concentration of BDNF, the fewer calories participants consumed and the greater the weight loss.
This suggests that BDNF acts as an appetite suppressant, the researchers said. They noted that identifying markers such as BDNF may help health care providers determine which patients will benefit from exercise.
The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about safe and successful weight loss.