Nutrient density

Nutrient density tells you how much substance there is in every calorie: vitamins, minerals, fibre, protein and phytochemicals in relation to energy. Broccoli, berries, lentils, quark and oats are nutrient-dense: plenty of goodness for few calories. Fizzy drinks, gummy bears and white bread sit at the other end – lots of energy, hardly any nutrients.

Why does this matter so much when you're trying to lose weight? If you eat less, you have less “room” for nutrients. Every calorie then has to work harder – otherwise, despite the calorie deficit, you risk tiredness, cravings or a lack of iron, calcium, iodine or B vitamins. The flip side: if you eat nutrient-dense foods, you stay full and on top form – even though your energy intake drops.

Nutrient density and energy density are two sides of the same coin. Vegetables have a high nutrient density and a low energy density, nuts are high in both, and sugar has a low nutrient density and a high energy density. The ideal is a base of foods with a high nutrient density and a low to medium energy density, topped up with small amounts of nutrient-rich calorie bombs such as nuts, seeds or oily fish.

Scientists use scoring systems for this, such as the Nutrient Rich Food Index (NRF9.3), which weighs nine desirable nutrients against three to limit (saturated fat, sugar, salt). The Nutri-Score follows the same logic. In everyday life, one question is enough: “Does this give me more than just calories?”

An easy route to more nutrient density: something colourful from the fruit and veg aisle at every meal, wholegrain instead of white flour, pulses and dairy as your protein base – and sweet things enjoyed consciously as a treat rather than as a staple.