Experimental psychologists at the University of Bristol have found evidence that individuals who were sticking to special low calorie meals, failed not only to shift the pounds, but were more likely to gain even more weight.

The researchers, led by Dr. Jeff Brunstrom, a lecturer at Bristol University, said that the explanation for this phenomenon is very simple - when people choose lower-calorie foods, they just compensate by consuming bigger portions. "A person's perception of how full a meal will make them feel will no doubt affect portion size," said Lisa Miles, a nutritionist at the British Nutrition Foundation. "It is so important to be aware of behavioral triggers for over-eating," Ms. Miles cautioned.

The team of experts, who analyzed the responses of 76 adults to 18 different types of food, revealed that people quickly became aware if food carried fewer calories per serving and increased the size of a portion in order to compensate. The study also showed that when offered the foods they liked, participants did not choose bigger portions of them than of any other food. From experimental studies it is well-known that consuming food in large portions does not necessarily mean that there will be less eating at a subsequent meal, Ms. Miles said, so this can result in an overall increase of calorie intake.

In a study, that is scheduled to be published later in June, Dr. Brunstrom also found that children whose parents limited their consumption of high-calorie snack foods such as chips, crisps and chocolate, were more likely to consume them in much larger portions when being presented with them.

The investigators examined 70 kids with the ages between 10 and 12 years old, offering them six types of snack foods and asking to estimate how much was too much. The results revealed that children who were allowed to buy sweets and crisps scored much better at guessing calorie levels. In contrast, a child who was not familiar with snack food was more likely to over-estimate how much he/she would need.

The findings demonstrate that restricting an access to certain unhealthy snack foods limits people's learning about their properties. Therefore, when people eventually encounter snack foods, they are likely to pick them in larger portions, Dr. Brunstrom explained. This could be sound as unpleasant news for parents/caregivers who are sure that they are doing their children a favor by placing treats such as sweets and cakes off-limits.

The most important lesson here is that the weight control is all to do with education, education, and one more time education, Tam Fry, chairman of the Child Growth Foundation and a member of the National Obesity Forum, said. The expert added that children, starting with early years, need to be introduced to portion size as a positive measure, otherwise it becomes a forbidden fruit which is always the most tempting one. And it is not just the ignorant person who is affected by extreme weight and obesity, it goes across all social classes.

The findings will presented at a British Nutrition Foundation conference, entitled "Satiation, satiety and their effects on eating behavior", on June 18.

Tags: Diets and Weight Loss

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