I still recall the first time I became cognisant of food calories. I had just polished off several courses of a lavish breakfast spread at the five star hotel where my consulting team was put up during an international project. My colleague, a fitness junkie, then in the pursuit of the elusive six-pack abs, had been observing the careful consideration I had put into picking up an eclectic mix of breakfast items. He waited patiently for me to wipe off the foam from the coffee, which served as the finale of my meal, before remarking casually, “You know you’ve exhausted more than 60% of your calorie quota for the day already, right?”

“You know you’ve exhausted more than 60% of your calorie quota for the day already, right?” 

“What!” That couldn’t be right. I had understandably eaten a big meal, but surely those dainty Danish pastries, choco-chip muffins, baked beans, cold cuts, and the egg-white omelette could not add up to that many calories! I consoled myself that since I was going to have ‘just a salad’ for lunch anyway, perhaps the big splurge was justified. I vaguely recall that the lunch did not end up being ‘just a salad’.

But I clearly recall that I spent a good part of my morning looking up the calories in various foods. That was over twelve years ago. And that’s how the initiation into my self-guided study of nutrition happened. The fascination has not stopped but now I’m well guided in this matter.

I’ve heard the refrain ‘A calorie is a calorie…is a calorie’ several times. The import of that statement is that what is important in a diet, regardless of the health goal, is the number of calories. At the most basic level (we’re talking survival here), this is correct. But if one has certain goals in mind, then it is critical to understand WHERE the calories come from, i.e. the three energy-providing macronutrients – carbohydrates, protein and dietary fat. Water, termed the fourth macronutrient at times and an essential nutrient at others, does not contribute any calories.

If one has certain health goals in mind, then it is critical to understand WHERE the calories come from. 

While each gram of carbs and protein provides 4 calories, a gram of fat provides 9 calories, more than double the energy of carbs or protein. So we would need fewer grams of fat than carbs or protein to provide the same number of calories. As a corollary, one should be able to eat more grams of carbs and/ or proteins vs fat to fulfil their calorie requirements, isn’t it?

Now, consider this. Fat takes up more than three times the space of the same quantity of protein in weight. Hence, 1 kg of fat will occupy at least three times the space of 1 kg of protein. This is the reason why two people with the same height and weight can look slim or obese depending on the proportion of body fat. More reason to consume fewer grams of fat, because who in their right mind wants to be fat, right?

Wrong!

The reason that we have had this upside down for so long is because of the understanding that all calories are equal. In reality, one must ask what type of calories we are talking about. This is because each macronutrient has a different role to play in our body. Carbs provide quick energy – their calories can potentially be burned almost as soon as they are ingested. Protein grows, repairs and maintains the body – muscles, organ tissue, blood vessels, hormones, enzymes, antibodies, hair, skin, nails, etc. Fat provides a long-term store of energy, regulates body temperature, enables brain functioning, and allows vitamin absorption.

Just as the role of each macronutrient in our body is different, so is the manner in which each is used by the body. Carbs are used for providing energy instantly and for aiding digestion if they are fibre-rich. Protein, although used primarily for growth and repair, can be used for providing energy in times of distress, when adequate energy from other sources is not available, but at the cost of muscle tissue. Body fat, stored as adipose tissue in the body, is used for providing energy only when other sources of energy are not available or when the body is in starvation mode.

Here’s the kicker – any calories from carbs and protein that are not used by the body are converted to fat in the form of adipose tissue! So much for avoiding dietary fat, huh!

So, which calories should one consume? I’ll talk about this in the following posts.

P. S. The self-guided ones might like to pick up Good Calories, Bad Calories by Gary Taubes, which puts to bed several arguments on calories. Will provide my own review of the tome soon.