HEALTH/FOOD SPECIAL...Fad diets often do more harm than good

Fad diets often do more harm than good

Fad diets are a bit like new infections, a new one pops up almost every year. Most die without a whimper, but some, like the common cold, get cult status and thrive for years, till a celebrity endorsing it dies of unexplained causes and the food fad gets buried in an unmarked, shallow grave.

After Atkins, Ornish, South Beach and Dukin diets, the newest rage is the Rasberry Ketone Diet, which was promoted as a fat-burning miracle in a bottle in The Dr Oz Show in the US earlier this year.

The supplement’s popularity started in East Asia after a 2010 Korean study reported raspberry ketone increase fat cells’ secretion of the hormone adiponectin that regulates sugar and fat processing in the blood. They were confirming a Japanese study that had found it prevented obesity and fatty liver by boosting the breakup of fat cells.

Now, the facts. In mice, in very high doses, raspberry ketones do alter fat metabolism and prevent weight caused by too much fat in their diet. But there is no medical evidence that they induce similar loss in humans. It's highly unlikely, say sceptics, because the doses fed to rats were 200 times higher than the human dose.

The red flag, of course, is the word 'ketones' that induce ketosis, which is an abnormal process that occurs during starvation. Ketosis can cause fatigue, constipation, nausea, and vomiting, and over time, heart attack, bone loss and kidney damage.

Diets that promote eating a supplement, one type of food over others or eliminating certain food types often induce weight loss initially, but this loss is seldom sustained. On the other hand, all low-calorie diets help people lose weight, regardless of how much protein, fat and carbohydrates are included.

Just cutting down a little on the fat in what you eat and you'll lose weight, said a study commissioned by the World Health Organisation in the British Medical Journal on Friday. You can lose weight without eating less comes was confirmed from a review of studies involving nearly 75,000 people who were not trying to lose weight. They lost the excess weight by simply switching to low-fat substitutes without making any other change to their meal-plan or lifestyle.

Overeating makes everyone overweight, but some more than others. You need 7,700 extra calories to put on a kg of body fat, so just cutting back on 500 calories a day can lead to a weight loss of about 2 kg a month, though it can vary with people.

Your genes controlling your metabolic rate - calories burned by your body to function through the day - and “spontaneous non-exercise activity” (fidgeting) can burn as much as 100 to 800 calories a day. If you are restless, you are less likely to be overweight, compared to your more slothful colleague.

When planning weight-loss, mind that the amount of calories you burn declines with age, by as much as 20% by age 50 and by 30% over age 70. Also, people with lean muscle muscles burn more calories doing the same activity than those with more fat, just as men burn more than women.

Successful weight loss -- losing weight and keeping it off for at least five years - is possible only through a healthy diet (staying away from highcalorific traps that a bag of chips or cookies can morph into) and getting more active (30 minutes of activity at a go that leaves you breathless at least five days a week).

• Sanchita Sharma, HT121209