A bowl built on the pairing the guava trial used — a fruit rich in vitamin C beside plant iron. Though the iron stores that trial named as its primary outcome did not rise.
2 servings30 min
Rinse the lentils and simmer them in 400 ml of water for 15 to 18 minutes. They are done when they hold their shape but crush under a finger.
Do not use a generous amount of water. Draining it takes the water-soluble vitamins with it. At 400 ml, almost all of it is absorbed.
Meanwhile, heat the olive oil in a pan and fry the onion for 3 minutes.
Add the garlic and the cumin and fry 30 seconds. Cumin needs oil to release its aroma.
Add the spinach, cover, and give it 1 minute. Off the heat as soon as it wilts — longer costs folate.
Put the lentils in a bowl, spoon the vegetables over, and season with salt and pepper.
Wash the guava and cut it into 2 cm cubes with the skin on. Do not peel it — the vitamin C concentrates there.
Add the guava last and pour over the lemon juice. It is not cooked — vitamin C does not survive heat.
This bowl carries the structure of the 2024 trial across.
2024, The Journal of Nutrition. Two hundred children aged 6 to 10 in rural Haryana, India, were fed through the school meal programme for seven months.
The iron was nearly identical; the only difference was vitamin C.
The results, precisely:
| Outcome | Result |
|---|---|
| Body iron stores (primary) | p=0.197 — not significant |
| Hemoglobin | 3.7 g/L greater rise (p=0.001) |
| Anemia prevalence | 51% greater fall (p=0.022) |
| Iron-deficiency anemia | p=0.087 — not significant |
The primary outcome was missed. The paper's title says so — it reduced anemia and increased hemoglobin, but not iron stores.
And its participants were children in a region where 71% were iron deficient. That is not a basis for someone who is not short of iron to expect the same from this bowl.
The reason to build the pairing anyway is that the principle behind it is established. That vitamin C raises the absorption of plant iron does not rest on that one trial.
Per serving:
| Per serving | |
|---|---|
| Lentils 60 g (dried) | 210 kcal, protein 15 g, iron 4.0 mg, fibre 18 g |
| Guava 75 g | 51 kcal, vitamin C 171 mg, fibre 4.1 g |
| Spinach 50 g | 12 kcal, iron 1.4 mg, folate 97 µg |
| Olive oil, onion, seasoning | about 90 kcal |
| Total | about 363 kcal, iron 5.4 mg, vitamin C 171 mg, fibre 23 g |
The 171 mg of vitamin C is almost exactly the trial's 170 mg. That is not a coincidence; it was matched.
Twenty-three grams of fibre is 82% of the daily value. If your usual intake is low, start with half a portion. A sudden jump is uncomfortable.
Why the guava is not cooked. Vitamin C is heat-sensitive and water-soluble. Boil it and much of it disappears, and with it the point of this bowl. Add it raw at the end.
Why the skin stays on. The vitamin C and fibre concentrate in the skin and just beneath. Wash it well and cut it whole.
Why so little water for the lentils. Boil them generously and drain, and some of the water-soluble vitamins and minerals go down the sink. At 400 ml, it is nearly all absorbed in 15 to 18 minutes.
Why the spinach gets only a minute. Folate does not survive heat and water. The moment it wilts is the end.
Keep tea and coffee away from this meal. Tannins interfere with iron absorption. If coffee after a meal is a habit, leave an hour. That habit works directly against the point of this bowl.
No guava? Kiwi (92.7 mg), strawberry (58.8 mg) or orange (53.2 mg) will stand in. You need more of them to match the same vitamin C.
If iron deficiency has been diagnosed, do not plan to solve it with this bowl. Food is an adjunct; a diagnosed deficiency is a matter for your clinician's prescription.
Fruits
Moderate evidenceA seven-month school-feeding trial in India. Hemoglobin rose and anemia fell. But body iron stores, which the trial had named in advance as its primary outcome, did not rise significantly. What happened and what did not have to be read apart.
Grains & legumes
Strong evidence7.9 g of fibre and 181 µg of folate per 100 g cooked. The LDL effect is settled across 38 randomised trials.
Vegetables
Moderate evidence"Spinach equals iron" is only half true. The real value sits in folate, vitamin K, and the lutein that accumulates in your eyes.