Do calories really matter?

Is the idea of resetting kcals to match modern sedentary lifestyles a waste of time?

"Oh no, I can't eat that, it's 1000 calories." There's a vague assumption in the back of your mind that 1,000 calories is a lot, but compared to what? New studies from the London School of Economics claim that existing calorie indicators, such as the recommended 2,500 a day for the average man, should be slashed to account for modern lifestyles. In the last 30 years, the amount of casual exercise, walking up stairs, to work and so on, has drastically decreased. Yet calorie counts have stayed the same.

Is it time for the rules to be redressed? We dive into the nitty-gritty and reveal calories as you've never seen them before.

If you’ve ever tried to lose weight, you’ve probably been told to “count your Calories”.

The idea is to consume less than you burn and you’ll shed the extra weight. But is it really that simple?

The short answer is yes. Excellent news. The long answer, however, is not quite. To understand this dichotomy, first we’ll explore the role of Calories, second of macronutrients (carbohydrate, protein, fat), and third of different forms these macronutrients might take.

A calorie is not a Calorie

What a calorie is


What a calorie isn't

A calorie (lowercase c) is not a Calorie (uppercase C). The latter is actually synonymous with a kilocalorie (kcal), so a thousand calories. The energy in food is measured in kilocalories, so you’ll need to count your Calories, not your calories — fortunately.

So why do most diets involve Calorie counting?

Well, to lose weight, you need to consume fewer Calories than you burn. To gain weight, you need to eat more.

(Related: Eat breakfast to burn more calories)

How many Calories you burn depends primarily on your resting metabolic rate (RMR) and level of activity. Simple? Yes. But misleading, too, because your body does its best to regulate its energetic expenditure, whether you eat too much or not enough.

So let’s break this down.

If you eat too much

You will store part of the extraneous energy as fat (as is commonly known) but you’ll excrete the rest (as is less commonly discussed).

If you don't eat enough

You risk experiencing a large decrease in metabolic rate: your body will agree to spend less energy, be it for the sake of exercising or just breathing, so you’ll feel more tired at the same time as your fat loss grinds to a halt. For that reason, try to keep your caloric deficit within 10% of your maintenance requirement (the amount of Calories you need to neither gain nor lose weight).

A Calorie calculator is a simple means of assessing your caloric needs. If you exercise irregularly, you might want to oscillate between a higher caloric intake on your workout days and a lower one on your rest days.

The rule to remember here is: you don’t need to obsess over every single Calorie you ingest. Just try to stay within 10% of your target number.

Even a Calorie isn't a calorie

As we’ve seen, losing fat isn’t as simple as reducing the number of Calories you ingest. But are all Calories equal, at least? With regard to dieting, hardly.

Let’s first have a look at macronutrients. One gram of fat represents 9 Calories, while one gram of carbohydrate and one gram of protein each represent 4 Calories.

Carbohydrate and protein are caloric equals (they’re isocaloric). Protein is more filling, however, its digestion requires more energy (thus more Calories), and its conversion into body fat is very inefficient — your body would rather use it to maintain your muscles and other lean tissues. On a low-Calorie diet, consuming enough protein helps preserve muscle mass, which matters since the goal is not to lose weight but fat.

For the MH man, protein is pretty important. So how much do you need? Well, the answer depends on your goal.

>To build muscle

Aim for 1.2–2.0 g per kilogram of body weight per day (0.54–0.91 g/lb/day).

To lose fat

Aim for 1.0–2.2 g/kg/day (0.45–1.00 g/lb/day).

And remember, the higher your caloric deficit, the higher your protein intake should be, though people with significant amounts of weight to lose should base their intake, not on their current body weight, but on their goal body weight.

Protein versus protein

Calorie for Calorie, protein is more filling than carbohydrate or fat, though less than a mix of all three macronutrients. What kind of protein you consume, however, has little impact on fat loss proper. It mostly affects muscle gain, and on a low-Calorie diet, muscle retention.

The protein you ingest is digested into amino acids. The amino acids your body needs and cannot synthesise are called essential amino acids (EAAs). Among EAAs, branched-chain amino acids (BCAAs), especially leucine, play a major role in muscle growth and preservation.

Most plant-based proteins are incomplete (they’re poor in one or more EAAs), but a varied diet will ensure that they complete one another. It is only if you choose to take a protein supplement that the source matters.

Whey and casein powders are both derived from milk protein. If you are neither lactose intolerant nor vegan, whey is an easy choice, for it is cheap and very anabolic (good for building muscle). Casein is more expensive but more anti-catabolic (good for preserving muscle). Since casein digests slowly, it is often seen as the ideal protein to consume before sleep.

(Related: How whey powder will help you lose weight)

But what if you are lactose intolerant or vegan? Fortunately, you can still supplement protein powders. Two popular options are soy, a complete protein, and a 70:30 pea:rice blend, which is seen as the vegan alternative to whey due to their similar amino acid profiles.

(Related: 10 foods to build muscle)

Carbs: the fast, the slow, and the fibre

Carbohydrates with a high glycemic index value (GI) are digested faster. The resulting shortened period of satiety is partly caused by an insulin spike. While this hormone is often vilified, its nature is that of a double-edge sword, since it helps shuttle nutrients where they are most needed — be that your muscle tissues or your adipose tissues (your fat stores).

As a general rule, “fast carbs” should be preferentially consumed during or shortly before/after exercise. At that time, you can choose to consume a mix of two or more sugars or other simple carbohydrates (glucose, fructose, maltose). Although maltodextrin is not a simple carbohydrate, its absorption rate is similar to that of dextrose (D-glucose), so it can be used as part of your mix.

To minimise the risk of gastrointestinal symptoms, your exercise beverage should only be 6-8% carbohydrate (a lot less than most sports drinks), of which half at most should be fructose. If you exercise for 45 minutes to 2 hours, aim for 30-60 g/hr; if you exercise longer, aim for 60-90 g/hr.

This counts as part of your daily carbohydrate intake.

Fibres don’t, on the other hand, since they can’t be digested. In fact, fibres might even help with fat loss, though most research has shown results to be marginal at best.

The skinny on fats

The difference between fats matters greatly from the standpoint of general health, but much less from the more restricted standpoint of fat loss or muscle gain. Trans fats might cause greater fat gains, just as conjugated linoleic acid (CLA) might help with fat loss, but neither to any great extent, and evidence is inconclusive.

Still, some fats are more easily digested and oxidised than others. Medium-chain triglycerides (MCTs), found in coconut oil, cheese, yoghurt and milk, tend to be quickly metabolised, making them less likely to be stored as fat. Most people get very little MCTs in their diet — less than 1.4 g/day. Consuming 2-12 g/day (as replacement for other fats) may bolster fat loss by increasing thermogenesis and satiety, but here again evidence is inconclusive.

Yes, Calories really matter, but...

Whether you wish to lean down or muscle up, counting Calories is important, but ultimately insufficient. Technically, yes, your low-Calorie diet could consist entirely of pastries, but you’d be starving most of the time, you'd become deficient in most minerals and nutrients and your lack of energy would force you to eat more.

While there’s no pastry diet (that we know of), actual fad diets can be nearly as restrictive, regulating both what you eat and when. Such diets often fail, if only because most people find them unsustainable. Consistency is key, so your diet should fit your preferences and lifestyle, within certain limits.

Whatever your health goal might be, you should favour whole foods over processed foods, especially junk foods; yet even the latter can be squeezed into your diet plan, as long they amount to less than 15% of your caloric intake. Yes, fatty foods do have a place in your diet.

But, our advice, keep your diet reasonably clean, try to hit your macros, then focus on your training and overall well-being.


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