Why We Get Fat – Part 2
Why we get fat – part 2 was published in The New York Times last year by David S. Ludwig and Mark I. Friedman.
Below you find Why We Get Fat – Part 2 of the article.
The video that follows is extremely helpful in understanding how the body processes food and stores fat. Be sure to watch it now.
What follows are important clues to understanding why there is such an obesity epidemic in the US and in many economically developed countries. This applies to most of the Western World.
As it turns out, many biological factors affect the storage of calories in fat cells, including genetics, levels of physical activity, sleep and stress. But one has an indisputably dominant role: the hormone insulin. We know that excess insulin treatment for diabetes causes weight gain, and insulin deficiency causes weight loss. And of everything we eat, highly refined and rapidly digestible carbohydrates produce the most insulin.
By this way of thinking, the increasing amount and processing of carbohydrates in the American diet has increased insulin levels, put fat cells into storage overdrive and elicited obesity-promoting biological responses in a large number of people.
Like an infection that raises the body temperature set point, high consumption of refined carbohydrates — chips, crackers, cakes, soft drinks, sugary breakfast cereals and even white rice and bread — has increased body weights throughout the population.
The explosion in processed foods for the last 50 years has subjected all of us to an ever increasing level of carbohydrates in our diets. You cannot easily get away from this unless you make a concerted effort to clean up your diet… easier said than done, especially if you have a modest food budget. Processed foods are relatively cheap.
Fat has about twice the calories of carbohydrates, but low-fat diets are the least effective of comparable interventions, according to several analyses, including one presented at a meeting of the American Heart Association this year.
A recent study by one of us, Dr. Ludwig, and his colleagues published in JAMA examined 21 overweight and obese young adults after they had lost 10 to 15 percent of their body weight, on diets ranging from low fat to low carbohydrate.
Despite consuming the same number of calories on each diet, subjects burned about 325 more calories per day on the low carbohydrate than on the low fat diet — amounting to the energy expended in an hour of moderately intense physical activity.
Another study published by Dr. Ludwig and colleagues in The Lancet in 2004 suggested that a poor-quality diet could result in obesity even when it was low in calories. Rats fed a diet with rapidly digesting (called high “glycemic index”) carbohydrate gained 71 percent more fat than their counterparts, who ate more calories over all, though in the form of slowly digesting carbohydrate.
So, why are just now finding out that excess carbohydrate are a leading cause of weight gain and obesity? Actually, many studies published in the leading medical journals have been warning against this for some time. They have just been ignored by the food industry.
These ideas aren’t entirely new. The notion that we overeat because we’re getting fat has been around for at least a century, as described by Gary Taubes in his book “Good Calories, Bad Calories.” In 1908, for example, a German internist named Gustav von Bergmann dismissed the energy-balance view of obesity, and hypothesized that it was instead caused by a metabolic disorder that he called “lipophilia,” or “love of fat.”
But such theories have been generally ignored, perhaps because they challenge entrenched cultural attitudes. The popular emphasis on calorie balance reinforces the belief that we have conscious control over our weight, and that obesity represents a personal failure because of ignorance or inadequate willpower.
In addition, the food industry — which makes enormous profits from highly processed products derived from corn, wheat and rice — invokes calorie balance as its first line of defense.
If all calories are the same, then there are no bad foods, and sugary beverages, junk foods and the like are fine in moderation. It’s simply a question of portion control. The fact that this rarely works is taken as evidence that obese people lack willpower, not that the idea itself might be wrong.
It might be appropriate to point out that many researchers have emphasized the difficulty of conducting nutritional studies because these studies frequently rely on participants recollection of what they ate. These responses are typically inaccurate.
UNFORTUNATELY, existing research cannot provide a definitive test of our hypothesis. Several prominent clinical trials reported no difference in weight loss when comparing diets purportedly differing in protein, carbohydrate and fat.
However, these trials had major limitations; at the end, subjects reported that they had not met the targets for complying with the prescribed diets. We wouldn’t discard a potentially lifesaving cancer treatment based on negative findings, if the research subjects didn’t take the drug as intended.
There are better ways to do this research. Studies should provide participants with at least some of their food, to make it easier for them to stick to the diets.
Two studies that did this — one by the Direct Group in 2008 and the other by the Diogenes Project in 2010 — reported substantial benefits associated with the reduction of rapidly digestible carbohydrate compared with conventional diets. We need to invest much more in this research.
With the annual economic burden of diabetes — just one obesity-related complication — predicted to approach half a trillion dollars by 2020, a few billion dollars for state-of-the-art nutrition research would make a good investment.
By using the results of these studies it is possible to begin to change the half a century of misguided guidelines provided by the government, and gladly taken up by the food industry. We can adopt a lifestyle change away from the over consumption of heavily processed carbohydrates.
If this hypothesis turns out to be correct, it will have immediate implications for public health. It would mean that the decades-long focus on calorie restriction was destined to fail for most people.
Information about calorie content would remain relevant, not as a strategy for weight loss, but rather to help people avoid eating too much highly processed food loaded with rapidly digesting carbohydrates. But obesity treatment would more appropriately focus on diet quality rather than calorie quantity.
People in the modern food environment seem to have greater control over what they eat than how much. With reduced consumption of refined grains, concentrated sugar and potato products and a few other sensible lifestyle choices, our internal body weight control system should be able to do the rest.
Eventually, we could bring the body weight set point back to pre-epidemic levels. Addressing the underlying biological drive to overeat may make for a far more practical and effective solution to obesity than counting calories.
David S. Ludwig directs the New Balance Foundation Obesity Prevention Center at Boston Children’s Hospital and is a professor of pediatrics at Harvard Medical School. Mark I. Friedman is vice president of research at the Nutrition Science Initiative.
In conclusion, better understanding of scientifically proven nutritional information will not only make it easier to select a diet that’s easy to follow, but such a diet will be healthier. Best of all, it will work!