Low-Energy-Density Fresh Produce

Berries

Berries including blueberries, strawberries, and raspberries are widely stocked in UK supermarkets, available fresh in punnets or frozen in bags. Berries have high water content (approximately 80-90%), contributing to their low energy density. Typical energy content ranges from 32-57 kcal per 100g depending on the type.

Berry Type	Energy per 100g	Water per 100g	Fibre per 100g
Blueberries	57 kcal	84g	2.4g
Strawberries	32 kcal	91g	2g
Raspberries	52 kcal	86g	6.5g

Vegetables

Common vegetables available year-round in UK supermarkets include carrots, broccoli, spinach, peppers, and tomatoes. These vegetables typically have high water content and low energy density, ranging from approximately 18-34 kcal per 100g for most varieties. Fibre content varies by vegetable type.

Vegetable	Energy per 100g	Water per 100g	Fibre per 100g
Broccoli	34 kcal	92g	2.4g
Carrots	41 kcal	88g	2.8g
Spinach	23 kcal	91g	2.2g
Red Pepper	31 kcal	92g	1.9g

Apples

Apples are year-round staples in UK supermarkets, available in multiple varieties. Apples contain approximately 52 kcal per 100g and have high water content (approximately 86g per 100g). The fibre content is found primarily in the skin and flesh, approximately 2.4g per 100g.

Apple Type	Energy per 100g	Water per 100g	Sugars per 100g
Granny Smith	52 kcal	86g	9.3g
Gala	52 kcal	86g	12g
Honeycrisp	52 kcal	86g	10.4g

Energy Density and Water Content

Water comprises a significant proportion of fresh produce, contributing to their lower energy density. Energy density is calculated as energy content (kcal) per unit weight. Because water provides no energy, foods with high water content have lower energy density per 100g compared to foods with less water.

The relationship between water content and energy density is direct: as water content increases, energy density decreases, assuming other components remain constant. This is why fresh produce typically has low energy density compared to dried fruits, nuts, or oils.

Cooking methods and processing can affect water content. Fresh produce naturally contains more water than processed alternatives, which may have water removed or reduced during manufacturing.

Fibre in Produce

Fibre is found throughout plant-based foods. In vegetables, fibre is distributed throughout the structure. In fruits like apples, fibre is concentrated in the skin and the insoluble cellulose of the flesh.

Raspberries are notable for their high fibre content (6.5g per 100g), whilst strawberries contain less (2g per 100g) despite similar appearance. Cooking or processing can affect fibre accessibility and digestibility.

The ratio of soluble to insoluble fibre varies by produce type and affects how the fibre behaves during digestion. Different fibre types are found in different plant structures.