Low-calorie, low fat diet better for your mood

A low-calorie, low-fat diet does more good to a dieters' mood than a low-carbohydrate plan with the same number of calories, says a new study.

Obese individuals who lose weight tend to have an improved psychological state, including a better mood, according to the study report.

Grant D. Brinkworth of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and colleagues conducted a randomised clinical trial involving 106 overweight and obese participants who aged 50.

Of these, 55 had been randomly assigned to follow a very low-carbohydrate, high-fat diet and 51 to a high-carbohydrate, low-fat diet for one year.

Changes in body weight, mood and well-being, and cognitive functioning (thinking, learning and memory skills) were assessed periodically during and following the one-year intervention.

After one year, the overall average weight loss was 13.7 kg, with no difference between the two groups. Both groups initially (after the first eight weeks) experienced an improvement in mood.

However, most measurements of mood revealed a lasting improvement in only those following the low-fat diet, while those on the high-fat diet returned to their initial levels (mood turned towards more negative baseline levels).

"The obesity epidemic has led to widespread interest in alternative dietary patterns for weight management," the authors write.

"While recent clinical studies have shown that low-carbohydrate diets can be an effective alternative dietary approach for weight loss, their long-term effects on psychological function, including mood and cognition, have been poorly studied.

"This outcome suggests that some aspects of the low-carbohydrate diet may have had detrimental effects on mood that, over the term of one year, negated any positive effects of weight loss," the authors write, according to a CSIRO release.

These findings were published in the November issue of Archives of Internal Medicine.

Rethink for calorie eating levels

The calorie counts used as the foundation for diet plans and healthy-eating guidance for the past 18 years may be wrong, a report suggests.

The recommended daily intake of calories could be increased by up to 16%, a draft report by the Scientific Advisory Committee on Nutrition said.

Intake levels are currently 2,000 calories for women and 2,500 for men.

But the panel stresses that people should only eat more if they exercise more, given rising levels of obesity.

The committee says its report provides a much more accurate assessment of how energy can be burnt off through physical activity.

A 16% increase would mean that adults could safely consume an extra 400 calories a day, equivalent to an average sized cheeseburger.

The proposals, seen by The Times and The Grocer magazine, are due to go out for a 14-week consultation period.

Final recommendations will then be made after that time.

Health campaigners say the Department of Health and the Food Standards Agency could seek to "sweep this report under the carpet" in a bid to avoid sending out mixed messages in the middle of an obesity epidemic.

Tam Fry, of the National Obesity Forum, said it was a "dangerous assumption" to say that adults could safely consume an extra 400 calories a day.

"This is not a green light to eat yourself silly," he said.