An Ironic Anti-Obesity Obsession
Of the macronutrients (carbohydrates, fat and protein), fat has been the most widely feared, from decades of misunderstanding.
It has has been said that consumption of fat raises the risk of obesity, heart disease, diabetes. Yet ever since the American Heart Association’s recommendation to reduce its consumption, these diseases are still on the rise - at a rate higher than ever. With the advancement of technology, more and more studies are refuting the dogma that fat is the culprit. The whole world might have shot itself on the foot, and only just discovered the bleeding.
So what is fat, exactly? Is it really unhealthy? If not, what made scientists think it was 50 years ago? And, what are today’s findings?
Fat, that fleshy thing everyone loves to hate, is actually a nutrient vital for normal bodily function. Not only does it provide us with energy, it is also crucial for nutrient absorption. Vitamins A, D, E and K need fat to be absorbed by the body. Fat also serves as insulation, and helps prevent infections.
Our bodies can use both fat and carbohydrates as fuel sources, but prefers fat, as it's more efficient. It gives off 9 calories per gram compared to 4 calories per gram of carbohydrates. Our bodies hold of using carbs until we engage in strenuous activities such as sprinting and weight lifting - as carbohydrate is a “faster” fuel - it allows for instant movement. When we rest, our bodies quietly burn fat. Picture an oil lamp. Using oil to fuel the lamp is more efficient as it burns slowly and steadily, lasting longer. If you use gasoline to fuel the lamp, it will give off more energy and burn faster. This is similar to how our bodies use fat and carbohydrates.
So how did we reach the conclusion that fat is bad? It all started with the now infamous nutritionist, Ancel Keys. In 1958, Keys conducted a study called the Seven Countries Study. In it, he examined the association between diet and cardiovascular disease in different countries. The study revealed that the countries where fat consumption was highest had the most heart disease, supporting the idea that dietary fat caused it. The problem is that he intentionally left out countries where people eat a lot of fat but have little heart disease, such as Holland and Norway, and countries where fat consumption is low but the rate of heart disease is high, such as Chile. Basically, he used data only from the countries that supported his theory. This highly flawed observational study gained massive media attention and had a major influence on dietary guidelines that still continue now. Succeeding studies seemed to support his findings when it was discovered that fat consumption increases total cholesterol which is linked to a higher risk of heart disease.
These studies gave rise to low-fat diets. The food industry quickly jumped in and created low-fat products loaded with sugar. People started reducing their total fat intake. In the US, the percentage of kcals from total fat decreased from 36.9% to 32.8% for men and from 36.1% to 32.8% for women. In addition, the percentage of kcals from saturated fat decreased from 13.5% to 10.9% for men and from 13.0% to 11.0% for women.
Still, lowering fat did nothing to prevent disease rates from rising. Although there was a drop in heart disease death rate, this is attributed to advancement in medical care and not due to lifestyle changes. Worldwide, the rate of obesity, one of the risk factors for heart disease, has doubled since 1980. A disease that used to affect mostly affluent nations is now widespread. It cuts across all social classes, attaining higher prevalence in poorer societies.
The reduction in fat intake made things worse. In fact, we are consuming more calories now than before, due to increased consumption of carbohydrates. For men, average energy intakes have increased from 2,450 kcals to 2,618 kcals, and for women, from 1,542 kcals to 1,877 kcals. For men, the percentage of kcals from carbohydrates increased between 1971--1974 and 1999--2000, from 42.4% to 49.0% and for women, from 45.4% to 51.6%. It's actually the consumption of carbohydrates especially from refined carbs that is causing this epidemic. But how?
Worse, fructose, a sugar that we are consuming more nowadays from refined carbs in food and drinks doesn't stimulate satiety, meaning, it doesn't curb our hunger - so we eat more. To understand this better, it's important to know how our body regulates our metabolism and how carbs and fat influence this. While important, weight gain goes beyond calorie counts.
By Shaun Ochia