Sometimes, even when a food is good for you, eating too much of it is not a good thing. It’s not just cake and French fries that can cause health problems when you eat too much.

Here is a list of 7 foods that are considered to be healthy—but that you should eat in moderation, since you could end up having health problems if you overdo it.

1. Oranges and Tomatoes

Although these wonderful summery fruits are nice additions to your diet, when you eat too much of them you could have problems with excess acid in your system. Excess acid can lead to a condition known as Barrett’s Esophagus, where erosion of the esophageal tissue occurs, leading to painful ulcerations and possibly precancerous lesions. Keep your orange and tomato intake to no more than two servings per day, or avoid them completely if you already experience acid reflux.

2. Water

Staying hydrated is critical to good health, but you can over-hydrate. When you drink too much water you can develop a condition known as water intoxication. Too much water will dilute the sodium that is in your body, which helps to balance the electrolytes. Monitoring your urine can help—it should be clear and light in colour, but if it is always completely clear then you may be taking in too much water and should cut back.

3. Canned Tuna

Many love the convenience and healthy option of a tuna sandwich or tuna salad. But, consuming too much of this canned fish may lead to having high mercury levels in your system. Tuna is known to contain higher mercury levels than many other types of fish. Too much mercury in your system can lead to problems with hearing, speech and vision, as well as muscle weakness and incoordination. Keep your intake to no more than 3-5 cans per week if you want to keep mercury out. Or, consider adding in other lower-mercury types of fish like salmon, shrimp and pollock.

4. Spinach

Loaded with nutrients and fibre, this leafy green also contains wonderful compounds like lutein, which is a carotenoid that helps protect your eyesight as you age. But, because spinach is also high in oxalate, it can lead to the formation of kidney stones. If you are prone to developing kidney stones, you may want to limit your intake of spinach.

5. Soy

Those who love tofu as a meat alternative to get their protein or control cholesterol and high blood pressure should know that taking in too much soy can lead to problems with anemia, since soy interferes with the absorption of iron. In addition, soy contains certain compounds that mimic estrogen, and therefore can be a problem for those with endometrial issues because they can be at a higher risk to develop endometrial hyperplasia, an overgrowth of the uterine lining that is linked with endometrial cancer. Keep your soy intake to no more than two servings per day.

6. Lean Animal Protein

Although low in fat and high in protein, lean animal proteins like chicken breasts or egg whites can cause a dangerous increase in insulin-like growth hormone production, called factor 1 (IGF-1). This hormone may speed up the aging process and also put you at a higher risk for developing certain types of cancer, especially breast cancer. Increasing the amount of protein that you get from plant sources can help. Eat more beans, nuts, seeds and whole grains in place of a few servings of lean animal proteins.

7. Brazil Nuts

A wonderful grab-and-go snack, Brazil nuts are loaded with protein, fibre, essential fatty acids and selenium. They are great for those trying to lower cholesterol and blood pressure. But, eating them every day can lead to high selenium levels, which can lead to hair loss, brittle nails, dermatitis, neurological problems, and even death in the most severe cases. Keep your Brazil nut intake to no more than 10 nuts per day.

Sure, all of these foods are considered to be healthy additions to your diet. But, like many other foods (even unhealthy options), keeping things in moderation is important for your health.