Onion is a fresh, whole vegetable and, as a NOVA group 1 food, delivers naturally occurring energy and nutrients with no added sugar, salt or additives. It adds vitamins, minerals and fibre to your day. One portion counts as one of your five a day. Work out the numbers for any portion and age below, then see the full macro and micronutrient breakdown.
The tables below put each macronutrient against age-appropriate guidance, because what matters for a 4 year old is very different from an adult.
1 medium onion (about 110g) contains about 5.2g of sugar, and it is all natural (intrinsic) sugar that comes packaged with fibre and water. It has 0g of added or free sugar, so it does not count toward the daily free sugar limit the NHS sets. The table shows those limits by age; Onion contributes nothing to them.
Onion is naturally very low in fat, with about 0.11g per portion and 0g of added fat. Only around 0.02g is saturated, well within the daily maximum for every age group.
Fibre supports healthy digestion, and most people in the UK do not get enough. A portion provides about 1.87g. Because children need less fibre than adults, that same portion covers a bigger share of a younger child's target.
There is about 10.2g of carbohydrate per portion. There is no single daily target, but roughly half of daily energy should come from carbohydrate; the reference values below are based on that.
Percentages are share of the daily Nutrient Reference Value (NRV). Under UK and EU rules a food is a source of a nutrient at 15% NRV per 100g and high in it at 30%.
These tables show how the nutrients compare to daily needs across different ages, using UK Reference Nutrient Intakes (RNIs). This differs from the source of and high in labels above, which use the single adult figure (NRV) set for food packaging. Children's needs are lower, so a portion goes further.
Folate is needed to make healthy red blood cells and is especially important before and during pregnancy. 1 medium onion (about 110g) contains 21ug. Because children need less than adults, that same portion covers a bigger share of a younger child's daily target.
Vitamin C supports the immune system and helps the body absorb iron from food. 1 medium onion (about 110g) contains 8.14mg. Because children need less than adults, that same portion covers a bigger share of a younger child's daily target.
Vitamin B6 helps the body release energy from food and supports the nervous system. 1 medium onion (about 110g) contains 0.13mg. Because children need less than adults, that same portion covers a bigger share of a younger child's daily target.
Potassium helps control blood pressure and supports normal muscle and nerve function. 1 medium onion (about 110g) contains 161mg. Because children need less than adults, that same portion covers a bigger share of a younger child's daily target.
Manganese contributes to normal bone formation and helps protect cells from oxidative stress. 1 medium onion (about 110g) contains 0.14mg. Because children need less than adults, that same portion covers a bigger share of a younger child's daily target. These figures use safe intake levels, as no formal UK RNI is set.
No. Onion is a NOVA group 1 whole food, the least processed category, eaten in its natural state with nothing added. The sugars are intrinsic, packaged with fibre and water, which is why whole vegetables behave very differently in the body from foods made with free sugars.
Nutrition data from McCance and Widdowson and UK FoodData Central, per 100g raw edible portion; values are reference figures and can vary by variety and ripeness. Reference intakes: EU NRVs for labelling and UK RNIs (SACN) for age-based needs. For guidance only.