A new study shows that state's intervention policies that aim to reduce obesity, and consequently reduce deaths due to heart diseases and diabetes, by encouraging low carbohydrate diets have little impact.

Researchers from Sweden analyzed medical records of 140,000 men and women in the past 25 years. They found that fat consumption by men dropped by 3 percent and by 4 percent in women in the year 1992. This change came about due to increased regulation in food labeling and promotion of low fat foods. But by 2005 this trend had reversed and more people were eating unhealthy foods.

The intervention program in Sweden, called the Västerbotten Intervention Programme, was launched in mid-eighties to reduce deaths due to heart diseases and diabetes. The aim of the project was to assess risk factors to each individual in the area and provide counseling about healthy lifestyle habits.

The present study was based on analyses of records by researchers from Umeå University, University of Gothenburg, and The National Board of Welfare.

"The association between nutrition and health is complex. It involves specific food components, interactions among those food components, and interactions with genetic factors and individual needs," said Ingegerd Johansson, lead researcher of the study.

Previous studies have shown that a diet that is low on carbs and high on fats especially in monosaturated fats helps people lose weight. Diets high in proteins are also considered more helpful than other diets. Restricting calories intake on the other hand proved ineffective in keeping people motivated to lose weight.

"While low carbohydrate/high fat diets may help short term weight loss, these results of this Swedish study demonstrate that long term weight loss is not maintained and that this diet increases blood cholesterol which has a major impact on risk of cardiovascular disease," Johansson added.

A study from 2000 says that there has been a significant increase in obesity and overweight rates in Sweden since 1980's and the trend picked up pace after 1996-97.