The nutrition and weight glossary

Nutrition terms, explained without the jargon. Every definition links to a proper source at the bottom of the page.

Calorie (kcal)

A unit of energy. Food provides it, the body burns it. What’s commonly called a “calorie” is actually a kilocalorie (kcal).

Calorie deficit

A situation where you eat fewer calories than you burn. The body then dips into its reserves, which makes weight go down over time.

Calorie surplus

The opposite of a deficit, eating more than you burn. Kept up over time, it leads to weight gain. The WHO describes this imbalance as the fundamental cause of overweight.

Resting metabolism

The energy the body burns at complete rest, to keep its organs running. It’s the biggest chunk of daily energy use for most people. Often estimated using the Mifflin-St Jeor equation.

Total energy expenditure

Resting metabolism, plus the energy used digesting food and doing everything from walking to sport.

Protein

Nutrients that build and maintain muscle and many tissues. 4 kcal per gram. ANSES places their share between 10 and 20% of daily energy for adults.

Carbohydrates

Sugars and starches, the body’s main quick source of energy. 4 kcal per gram. ANSES recommends they provide 40 to 55% of daily energy.

Fat

Essential, including for certain vitamins and for cells. 9 kcal per gram, the most energy-dense nutrient. ANSES places its share between 35 and 40% of daily energy.

Fibre

Parts of plants the gut doesn’t fully digest. They help you feel full and support healthy digestion. ANSES recommends around 30g a day for adults.

Added sugars

Sugars added to food and drinks during manufacturing or preparation, plus sugars from honey and syrups. The WHO recommends keeping free sugars below 10% of energy intake.

Macronutrients (or macros)

The three main nutrients that provide energy, protein, carbs and fat. Kiloach shows them alongside fibre, in four rings.

Standard alcoholic drink

In the UK, measured in units, 1 unit equals 8g of pure alcohol, roughly 56 kcal from the alcohol alone.

Smoothed weight curve

An average that irons out day-to-day swings (water, salt, digestion) to show the real trend. It’s the one Kiloach shows in your Stats.