Wednesday 18 March 2015

Obesity : A New look at an Old problem


A recent study published in Lancet medical journal revealed that rapid weight loss may actually be more beneficial than gradual weight loss. This is a departure from the usual advise we give patients to go slow to allow your body time to adjust.


Lets have a brief look at the problem of obesity.

Definition of Overweight and Obesity


BMI above 27.5 is considered Obese.

What is the size of the problem locally?




The minority ethnic groups seem to be affected more, especially the females (more than 50% overweight).


So what causes obesity?


We have the usual explanations of obesity as listed below



But we also have new studies that indicate that epigenetics may play a role in the obesity pandemic we are seeing.

1. Breastfeeding seems to reduce obesity.

2. Adequate sleep also seems to be an important factor to prevent obesity.

3. Leptin is a hormone releases by fat cells to increase satiety (feeling of fullness). Obese patients seem not to respond as well to Leptin (similar to Insulin resistence) . We are not sure why this resistence sets in or how to treat it. But some common sense diet advise seems to help. Reduce high Glycemic Index foods, reduce carbs and increase protein / fibre.

4. Fasting for 12 hours a day ( or at least not snacking for 4 hours between meals) also seems to help. In contrast, frequent snacks in between meals seems to increase obesity. This is independant of the calorie load that snacks present.


We also now view obesity as a form of inflammation with other factors that influence it besides simple calorie intake. Inflammatory markers in the blood rise with obesity. Lifestyle changes that reduce inflammation seem to reduce obesity.


Despite all this new knowledge, the secret to weight loss has not changed over the past decades. It is still to decrease caloric intake and increase energy expenditure. But with some new advise in diet and lifestyle changes.

Now, back to the Lancet study that started this article.

Brief overview of the study
1200 obese individuals were studied for weight loss either in a 3 month or 9 month weight loss program. The target was to lose 15% of their weight. After weight loss they were followed up for another 2.5 years and observed for weight increase in the maintenance phase.





In the study, both groups achieved weight loss, but the Rapid Weight Loss group showed higher percentage (81% compared to 62%) achieving the target weight.
 

As expected, during the 144 weeks maintainance phase, both groups regained back some weight (about 70%).


Despite gaining back about 75% of the lost weight, blood tests showed beneficial physiological hormonal changes were present.

Summary of Findings