Carbs: how many you need and when it matters

Carbohydrate is the macronutrient that attracts the most argument and, for most people, deserves the least. It is a fuel with no strict requirement, which sounds like an indictment and is not.

The three kinds

Sugars. Glucose, fructose, sucrose, lactose. Present naturally in fruit and milk, added to most processed food.

Starches. Long chains of glucose: rice, wheat, potato, millets, maize.

Fibre. Carbohydrate the small intestine cannot digest. Counted as carbohydrate on labels, yields much less energy, and does most of the useful work — see fibre, fullness, and the macro nobody counts.

Why there is no minimum

The body can synthesise the glucose the brain needs from protein and from the glycerol backbone of fat. This is why very low-carbohydrate diets do not incapacitate people.

It is frequently offered as evidence that carbohydrate is unnecessary. That conclusion does not follow. A requirement is a floor below which something breaks; the absence of one says nothing about whether the nutrient is useful above zero.

What carbohydrate is actually for

Fuel for hard efforts. Glycogen is the fuel for repeated high-intensity work. Training in a depleted state feels flat and usually produces less total work, which over months means less progress. This matters more as training volume rises.

Fibre. Nearly all dietary fibre comes attached to carbohydrate-containing foods.

Micronutrients. Fruit, vegetables, whole grains and pulses are carbohydrate foods and they are where a large share of vitamins and minerals come from.

Enjoyment and adherence. Under-rated and decisive. A diet you dislike is a diet you abandon, and for most people raised on rice or roti, a very low-carbohydrate diet is one they dislike.

How much, practically

The order of operations:

1. Set calories from your own measured intake, as in how to calculate your calorie deficit properly.
2. Set protein at 1.6 to 2.2 g per kilogram if you train.
3. Set a fat floor of 0.5 to 0.8 g per kilogram.
4. Carbohydrate takes whatever remains.

For a 70 kg person eating 2,000 kcal with 130 g of protein and 60 g of fat, that leaves about 245 g of carbohydrate, or 3.5 g per kilogram. That is a normal, workable intake and nobody had to argue about it.

Why low-carbohydrate diets seem to work so fast

The first week of a low-carbohydrate diet reliably produces a dramatic drop on the scale. Almost none of it is fat.

Glycogen is stored with roughly three grams of water per gram. Depleting it releases that water, and a two to three kilogram fall in a week is common. Reintroduce carbohydrate and it returns just as fast, which is where a great deal of dieting despair comes from — the mechanism is in water weight: how much it hides and for how long.

When calories and protein are matched, low-carbohydrate and higher-carbohydrate diets produce similar fat loss over meaningful periods.

When lower carbohydrate genuinely helps

It is a preference that suits some people, and the reasons are real.

Appetite. Some people find protein and fat more satiating and simply eat less on a lower-carbohydrate pattern.

Blood glucose management. For people with insulin resistance or type 2 diabetes, carbohydrate quantity and type matter clinically. That is a conversation for a doctor, not a blog.

Simplicity. Removing a whole category is easier for some people than moderating it.

None of these is "carbohydrate is fattening". All of them are legitimate reasons to choose a lower intake.

Timing and the night-time myth

Eating carbohydrate in the evening does not cause fat gain. Total daily intake determines weight change.

Some people sleep better with carbohydrate at dinner; some prefer it around training. Both are reasonable, and neither changes the outcome measurably. The same logic applies to protein, discussed in protein timing: what matters and what doesn't.

Quality within the category

Within a fixed carbohydrate intake, the choices that matter are fibre and how processed the food is.

Whole grains, pulses, fruit and vegetables come with fibre, water and micronutrients. Refined flour, sugar and fruit juice do not. Both log the same in a macro tracker, which is a limitation of macro tracking rather than a statement about the foods, and it is why what macros are, and which ones are worth counting ends with a warning about exactly this.