Sardines are often called one of the most nutrient-dense foods you can eat — small, cheap and packed with protein, omega-3s, calcium and vitamin D. But how often should you actually eat them?

Nutritionists say a few times a week is the sweet spot for most people. The American Heart Association recommends two servings of fish weekly, and sardines count. The US Food and Drug Administration lists them as a ‘Best Choice’ for children and pregnant women because they are low on the food chain and accumulate little mercury.

Their soft, edible bones are an excellent source of calcium, and they are one of few foods that naturally contain vitamin D, which helps the body absorb calcium. They also deliver EPA and DHA omega-3s that support heart and brain health.

There are catches. One can has around 282 mg of sodium — over 12% of the daily limit — so check labels if you watch salt intake. Sardines are also high in purines, which can trigger gout flares.

Bottom line: two to three servings a week fits most balanced diets. Choose tins packed in water or olive oil if sodium worries you.