Why a Zero-Calorie Label May Not Mean What You Expect

There’s a long-running joke that broken cookies don’t count for calories. The thinking is that tiny crumbs are so small they can be ignored, allowing you to eat them without worrying about the impact. In practice, federal food-label rules work in a similar way: anything with fewer than 5 calories can legally be labeled “zero calorie,” even if it technically contains some calories. That may seem insignificant, since it is basically just rounding down.

But bites, licks, and cookie crumbs can add up quickly. The smaller the portion, the easier it is to lose track and eat several servings. For example, if you ate 10 very small servings of a product labeled zero calorie that actually contained just under 5 calories per serving, you would still consume nearly 50 calories while likely counting none of them. The same logic applies to tasting batter or scraping up a bit of leftover dough here and there; before long, those small amounts can equal the calories in a couple of cookies.

That can make it frustrating to choose what seems like a healthier option only to learn it is not truly calorie-free. The upside is that products labeled zero calorie still have to be very low in calories. And, of course, overall health depends on more than calories alone.

Common “zero calorie” foods that can still contain calories

Food labels can be misleading, especially when it comes to calorie counts. The best way to avoid accidentally piling up calories is to know which items are genuinely close to zero and which ones merely appear that way. Water is the only food or drink that truly has zero calories, but several items come close enough to qualify for the label. Cooking spray is one example: it usually contains about 2 calories per spray, and it often takes many sprays to coat a pan. Cinnamon is another surprise, with as many as 6 calories per teaspoon, even though it is commonly treated as calorie-free in drinks and recipes. Flavored waters and sugar-free mints can also contain more calories than people expect.

On the other hand, some foods often thought of as zero calorie really are very close. Celery is a good example, with about 14 calories per cup, and it is also rich in nutrients and associated with benefits ranging from heart support to helping clean teeth. Spinach has only about 7 calories per cup and offers a range of health benefits, including support for eye health. Watermelon, true to its name, is high in water content and has about 46 calories per cup, while remaining very low in fat, sodium, and cholesterol.