If you look at the significant causes of mortality and long-term illnesses in today’s world, obesity stands head and shoulders above all other health risks.
The World Health Organization has tracked obesity and overweight for the last few decades and has declared that present-day obesity statistics are more than two times the numbers that was recorded in 1980. In fact, obesity and overweight are responsible for more deaths, worldwide, than sub-optimal body weight.
If you read the WHO factsheet, the statistics are alarming. The most heartening statement, however, comes in the end, that obesity is preventable!
The scientific community has devoted considerable effort towards understanding the innate mechanisms of management of fat storage in the human body.
Regulation of dietary intake is definitely one of the ways to control obesity and overweight. We are the net result of our diet and our energy expenditure in the form of various physical exertions. However, eating and diet regulation is not simply a matter of straightforward arithmetic of eating less ‘number’ of calories and spending ‘more’ calories. We also need to pay attention to the types of foods that we consume.
One of the changes brought about by urbanization and modernization is the change in food choices. Over the last 2-3 decades, the amounts of saturated fats and the total intake of fats has decreased in the Western diet. There has been a shift toward eating unsaturated fats. There are two major classes of unsaturated fats- Omega-3 and Omega-6.
Some 30 years ago, the ratio of these fats, in the standard diet, was Omega-6 : Omega-3 at1:1. That means that people consumed equal quantities of both these types of unsaturated fats. If you look at Western diets, today, the ratio has shifted to Omega -6 :Omega-3at 20:1!! In fact, modern agricultural practices have changed the natural proportion of fats in plants and animals. So, even if your food choices are healthy, chances are that you might still be ending up with more omega-6 than omega-3 fats.
Why is the Omega-6 / Omega-3 ratio a problem?
The total management of fat storage in the human body is the result of complex interplay between several processes. One of the processes is the accumulation of fat within fatty (adipose) tissue and the usage of that stored fat for generating energy and heat. Excessive intake of omega-6 fats induces your fat cells to take in more and more fats from your diet. The formation of new fat cells is also increased by omega-6 fats. Our body has two types of fat cells, white and brown. Brown fat cells are good for us because they generate heat from stored fat. White fat cells, on the other hand, serve to store more and more fat. The interesting effect of the imbalance between omega-6 and omega-3 fats, is that when omega-6 fats are predominant, they prevent the conversion of white fat cells to brown fat cells.
Another biochemical process, within our body, which is a delicate balance between defense and self-destruction, is known as ‘Inflammation’. As the name suggests, acute or cause-related inflammation can serve as a ‘fire alarm’ in some situations and invite the generation of molecules that actually cure the problem. Wound healing or the formations of a bump around the site of a bug bite are examples of such actions. In such cases, the root cause of the red flag- inflammation- is resolved and the inflammation is also brought down to zero.
Chronic inflammation, on the other hand, actually promotes disease rather than resolving it. Formation of plaques that block arteries is one such example of chronic inflammation. These two kinds of inflammation are caused by two teams of biochemical molecules. These molecules are derived from omega-6 and omega-3 polyunsaturated fats.
When the dietary intake of omega-6 fats is higher than that of omega-3 fats, the biochemical players in the chronic inflammation team become dominant. This leads to effects like formation and growth of arterial plaques, obesity and cardiovascular complications like stroke. In fact, inflammation is now recognized as the starting point of many long-term diseases.
Coming to omega-6 fats, there are other ways in which these fats promote obesity as well.
Obesity in children is another significant health issue. If a child’s diet has too many omega-6 fats, obesity begins to take root in childhood and weight management in later life becomes an uphill task for such people.
There are some studies that show that a diet rich in omega-6 fats also leads to leptin resistance. Leptin is the hormone that signals to the brain that food intake is enough. Now, the paradox that baffled scientists for a long time is that leptin is produced by fat cells. Obese people have more fat cells and therefore produce more leptin. Now, although this is true, the leptin produced by obese people is not effective in communicating with the brain. Hence, the system of the communication between the gut and brain is disturbed in people who consume more omega-6 fats than omega-3 fats. Now, this leads to an evil cycle of obesity and uncontrolled hunger wherein people seek more food.
The hunger system in the brain is also regulated by molecules called endocannabinoids. Excessive signaling by endocannabinoids leads to inflammation and obesity. These endocannabinoids are bumped up when we consume excessive omega-6 fats as compared to omega-3 fats. Omega-3 fats, in fact, decrease signaling via endocannabinoids.
|Omega-6 fats||Omega-3 fats|
|Increase inflammation||Decrease inflammation|
|Increase the number and size of fat cells||Decrease the production of fat cells|
|Disrupt the endocannabinoid system||Do not disrupt brain signaling via the endocannabinoid system|
|Leads to insulin resistance and leptin resistance||Does not disrupt insulin and leptin systems|
Conversely, omega-3 fats reduce inflammation in the body. These fats also help in controlling hunger. Moreover, omega-3 fats promote the conversion of white fat cells to brown fat cells. So, this means that stored fats are burnt to produce heat energy to keep the body warm.
So, it follows that omega-6 and omega-3 fats have opposite effects in the management of obesity.
Restoration of Balance
Scientists have created transgenic mice that express a gene from another organism. This gene makes an enzyme that can convert omega-6 fats into omega-3 fats. Here’s the interesting part. When such mice are fed a diet rich in omega-6 fats, they do NOT become overweight or obese. They do not develop cardiovascular disease or suffer from strokes. At the same time, these animals did not develop chronic inflammation (assessed by blood test).
So, summing up so far, if your diet has a good balance between omega-6 and omega-3 fats, you are less likely to suffer from obesity.
The next question, one would naturally ask, is what happens if you change your diet to include more omega-3 fats and less omega-6 fats. Now, there have been some studies conducted with people on whether supplementation of the diet, with omega-3 fats, can reduce obesity or not. Although results from other studies indicate that obesity should be reduced, results from human trials have been conflicting. Nonetheless, the fact that the pre-industrial diet was a balanced diet in terms of omega-6 and omega-3 fats AND obesity was NOT an epidemic, in those days, is an encouraging sign. Overall, there is good evidence supporting the idea that we need to have more omega-3 fats and less omega-6 fats within our system.
Why Focus on Dietary Balance?
Here’s the kicker. Omega-6 and omega-3 fats are essential fats. We cannot produce them, so we need to consume them, and we also lack the enzyme that converts omega-6 to omega-3 fats. Hence, our best bet is to eat less of the omega-6 six and eat comparatively more of the omega-3 fats. One must remember that management of obesity is not just a function of dieting or eating right. A good exercise regimen is also equally important. Free range meats and organic produce, grown with traditional agricultural methods, are likely to be the best sources of omega-3 fats.