A Mechanism Behind the Yo-Yo Effect

 

The yo-yo effect in dieting is something that has been observed for a long time- someone tries to lose weight but gains it all back right after the diet. Recently, scientists have discovered a mechanism behind the yo-yo effect that could help explain why it occurs. By analyzing fat cells from overweight mice and of mice that lost weight through dieting, it was revealed that obesity leads to characteristic epigenetic changes in the nuclei of the fat cells. These changes were found to have remained even after the loss of weight, where the cells remember the overweight state and find it easier to return to it. The mice with those epigenetic markers were able to gain the weight back faster when they resumed a high fat diet. A similar study was carried out on humans and the results were found to be consistent with the mice study.

In my opinion, this is a study that has produced useful information. By discovering a mechanism for why the yo-yo effect occurs on the molecular level, we can better understand how and why it occurs in humans. We could perform more research on this topic in order to potentially develop strategies to prevent it from happening to people who are trying to lose weight and keep it off. This study could have many benefits for many of these people.

Fat? Thin? Molecular switch may turn obesity on or off

Identical twins are usually alike in everything but; can diverge in one important characteristic, their weight. A new study uncovers a molecular mechanism for obesity that might explain why in twins, one can be extremely over weight even while the other is thin.

Heredity influences whether we become obese , gene researchers have found this link but yet doesn't explain the many differences in weight among people. Identical twins with non-identical weights are a prime example.

Researchers are now taking a closer look at this phenomena to see what accounts for this variation. Could it be changes in the intestinal micro-biome (Collection of bacteria living in the gut) or is it epigenetic changes (Alternations in gene activity)? These changes occur when molecules latch on to DNA proteins, turning sets of genes "on" or "off". Triggered by the factors in the environment, epigenetic modifications can be passed down from one generation to the next.

Physiologist J. Andrew Pospisilik of the Max Planck Institute of Immunobiology and Epigenetic's in Germany noticed an odd pattern of weight gain in mutant mice. After DNA testing the mice only had one copy of a gene called Trim28, the researcher found that most of them were obese. Trim28 is an epigenetic modifier which implicates it is a major gene in the bodies weight management. The exact functions remain unclear, but Pospisilik and colleagues hypothesize that Trim28 helps form an epigenetic switch that can flip on obesity by suppressing these genes.

Could this be the same mechanism to cause obesity in humans?

 The thing is mice only have one copy vs humans who have two. To compare, the team took fat samples form obese children in hospitals as it turns out Trim28 activity was abnormally low in those kids. The researchers then analyzed data on 13 pairs of identical twins in which one twin was obese.

Trim28 was diminished in the fat of the obese twin,  could this be the key to obesity ? This opens up the possibility of DNA screening at birth to see in fact if that new born will be obese.

This study gives a new potential mechanism of obesity and is a step closer to prevent or even reverse the condition of obesity.