In my last post, I recounted my initiation into calorie research. Like many rational and reasonably intelligent people, I arrived at the same conclusions that others do: fat eats into the calorie quota quickly, and it takes up too much space in the body, and, thus, would make me gain body fat. So, I should eat as little fat as possible, which will result in two benefits – I get to eat more, and I don’t get fat!

I soon became a pro at figuring out which foods contained fat and which didn’t, reading food labels for their fat content, looking for skimmed and low-fat options on supermarket shelves, and even cooking fat-free meals. Despite all this diligence, I could avoid neither the hunger pangs nor the weight gain. The way my requirement for larger clothes was going, I knew the weight gain was from fat, not muscle. It was definitely not dietary fat that was making me gain fat thanks to my thoughtfully crafted low-fat diet. Then what was making me fat?

Ever been through this before or know someone who has?

The answer lies in the inequality of calories. A calorie from fat will always remain a calorie from fat, and be stored as triglycerides, until it is required for providing energy. Calories from carbs and protein, however, are talented – they can change form. Carbs that are unutilised by the body are converted to fat and stored for later use. Any protein that is excess, after completing the job of growth, repair and maintenance, also converts to fat.

OK. That explained the metabolism issue, or the lack thereof. But surely the body should have been able to tolerate some amount of fat, especially if it was not getting any from my diet! ‘Some’, yes, but what about the body fat that was already sitting there and not getting used?

The human body has evolved over a couple of thousand millennia to use its resources in the most efficient way possible. For our ancestors of the Stone Age, starvation was a real situation that presented itself every so often. The store of fat in the body was what kept them going during those periods, which could very well last a couple of days or a few weeks. The reason being that the body has unlimited potential to store fat. Our ancestors, however, were different from us in that their bodies knew how to metabolise fat since they needed to do it frequently. On days that they got enough to eat, their bodies used the quick-energy providing foods, i.e. carbs, for immediate uses, and stored dietary fat as, well, fat. Obesity, hence, was a rare occurrence, if at all, since the body was adapted to burning fat.

With the advent of agriculture, about ten millennia ago, a dramatic shift occurred in the eating habits of human beings, since vegetables, fruits, grains and legumes, largely carbohydrates, became far more easily accessible to wide proportions of the population. With a rise in their consumption, the body started adapting to a sugar-burning mechanism (all carbs essentially being a form of sugar, once the fibre is removed). Now, the human body can store only about 2,000 calories worth of carbs at any given time, basically enough to last a day or at most two, versus an average of 30,000 calories from fat.

The food processing industry amplified this change by an order of magnitude. And guess what types of food were processed the most? Carbs! From raw vegetables and fruits to fibre-less juices and sugar-laden smoothies, from dehusked grains to polished ones, flours and breads, from steamed, whole tubers to dried and fried snacks.

With human bodies having essentially switched over to becoming sugar-burning factories from the highly optimised fat-burning, muscle-sparing ones, requiring feeding at small intervals (mostly carbs again) is it any wonder that rates for obesity, not to mention diabetes, have broken all records in the past hundred years?

What we actually needed to do was not cut out the fat from our food but to reduce the proportion of carbs, especially the processed ones.

So, how does one switch back to the fat-burning metabolism without subjecting oneself to starvation? That story begins with understanding ‘metabolism’. And I’ll get to it soon.

For those who like to do their own research, look up The Art and Science of Low Carbohydrate Living by Jeff S Volek and Stephen D Phinney.