Spinach · cooked

Spinach is among the lowest-calorie vegetables (23 kcal/100 g cooked) while being rich in iron, folate, vitamin K and fibre. It adds volume and micronutrients at an almost negligible calorie cost.

Its protein content (2.7 g) is minor: count it as a 'health' vegetable more than a protein source.

Raw in a salad, or cooked (it shrinks a lot) in an omelette, a stir-fry, a curry or alongside fish. A large raw amount reduces to a small cooked portion — handy to concentrate the micronutrients.

Spinach contains iron, but of plant origin (non-heme), less well absorbed than iron from meat. Pairing it with a vitamin C source (lemon, pepper) improves absorption. It usefully tops up intake, without replacing animal iron sources.

Spinach carries a reputation as a 'super iron source' that is partly exaggerated (an old decimal-point error on its content, popularised by Popeye). It does contain iron, but this plant iron is poorly absorbed, and the oxalates it holds slow assimilation a little further.

The practical takeaway: spinach stays an excellent health vegetable (folate, vitamin K, fibre), but don't rely on it as your sole iron source. Pair it with vitamin C, and keep animal sources or monitoring if you are at risk of deficiency.

Spinach cooks in just a few minutes. Toss it into a hot pan with a drizzle of oil or a little water, stir until it wilts (2 to 3 minutes), then season. A short steaming or pan-cooking preserves heat-sensitive vitamins better than a long boil, where part of the folate and vitamin C ends up in the cooking water.

Squeeze it lightly after cooking if you add it to an omelette, a quiche or pasta: the excess water would otherwise dilute the dish. Add garlic, nutmeg, lemon or a spoonful of plain yogurt to lift the slightly metallic taste. Reminder: the 23 kcal/100 g figure applies to cooked spinach; the cooking oil is what really raises the total.

Fresh spinach, in bunches or bags, is ideal in salads or for quick cooking; pick dark green, firm leaves with no yellow or slimy patches. Frozen spinach is harvested and frozen very quickly: it keeps excellent levels of folate and vitamin K, costs little and cuts waste. It is often the most practical solution on a tight budget.

Canned spinach is fine in a pinch, but check the label: some preparations contain cream, salt or additives that change the macros. To match the values on this page, choose plain spinach with no cream or béchamel, and weigh it cooked or drained, keeping the same convention in your tracking.

Fresh leaves keep 3 to 5 days in the fridge, in their bag or a box lined with paper towel that absorbs moisture. Wash them in cold water just before use, with several rinses: soil and sand hide in the folds. Baby leaves sold ready to eat are already washed, but a quick rinse does no harm.

Two points of caution. First, vitamin K: very abundant in spinach, it can interfere with some anticoagulant medications, so if you are on treatment, keep intake regular and talk to your doctor. Second, oxalates: if you have a history of kidney stones, ask for medical advice before eating a lot, especially raw and in large amounts.

When cutting, spinach is a volume ally: a big cooked plate weighs almost nothing in your calorie budget while delivering fibre, potassium, magnesium and folate. Add it to an egg white omelette, a chicken salad or alongside a turkey cutlet to make the meal more filling without leaving your deficit.

When bulking, it is not an energy source: don't let it fill your plate at the expense of the carbohydrates and protein you need. Keep it as a micronutrient complement next to a salmon and quinoa bowl or a beef and sweet potato bowl, which bring the calories and protein that muscle building requires.

Common mistakes: weighing raw spinach when the page values are for cooked (it shrinks by about three quarters), counting it as a protein source, or boiling it for a long time then discarding the water. Another trap: cooking it with cream, which turns a 23 kcal vegetable into a much more caloric dish.

As for alternatives, Swiss chard, kale, arugula, watercress or mustard greens offer similar micronutrient profiles. Rotating these leafy vegetables varies your intake and limits repeated exposure to a single family of compounds such as oxalates. Broccoli and edamame complete them well for fibre and a little more protein.

Pair spinach with a vitamin C source (lemon, pepper, tomato) to improve absorption of plant iron, and with a little fat (olive oil, whole egg, salmon) to better absorb fat-soluble vitamins such as K, A and E. The calcium in dairy binds oxalates in the gut and limits their absorption: a yogurt or a little feta on the plate is therefore a good reflex.

On the other hand, avoid having it right alongside a very strong tea or coffee at the same meal: tannins further reduce absorption of non-heme iron. Space them out by about an hour if you are trying to optimise your iron intake, especially if you are a female athlete or a vegetarian with higher needs.

In the morning, add a handful of spinach to an omelette, scrambled eggs or a smoothie: the taste almost disappears, the green colour stays. At lunch, wilt it into pasta, a chickpea curry or a chicken and feta salad. In the evening, serve it alongside a grilled turkey cutlet or a salmon fillet with a squeeze of lemon.

For weekly meal prep, frozen spinach is perfect: add it straight to the pan or the oven, and it releases its water and blends into the dish. Count roughly 150 to 200 g of frozen per person, and remember to drain it to avoid a dish that is too watery.