If you’re like me, any time you log onto Facebook you’re accosted by posts from high school friends (who you have to friend, right?) schilling one amazing MLM diet program or another.  The pitches sound tempting, but the reality is that you can get most of the benefits of one of those programs with planning and hard work – which are the best ways to get anything.

Take, for example, these five so-called negative-calorie foods.  “Negative-calorie” means that your body will burn more calories digesting them than the foods themselves contain.  That claim requires a little bit of magical math, but I’ll explain that in a moment.  First, the foods:

1.  Celery
Although celery is a powerful food with anti-inflammatory properties and apigenin, which may reduce the risk of developing ovarian cancer, it is also ridiculously low in calories.  A cup contains just 19 calories.

2.  Greens
Lettuce (and other salad greens) contain phytonutrients that are good for us, but they consist almost entirely of water, also yielding very low caloric values.  (Darker greens generally have higher nutritional value)

3.  Pickles
A cup of cucumbers contains about 16 calories, and as long as they’re pickled without sugar the caloric value remains low.

4.  Onions
Onion also contains very few calories by its weight (64 in a cup), but it delivers some serious nutritional value that can help to reduce the risk of cancer and improve your immune system.

5.  Kelp Noodles
Unlike most of the noodles we eat, good kelp noodles are made from kelp pulp, and like other greens they’re made up mainly of water.  They fall into the same category as greens, but because they’re in noodle form they can be substituted for starchy noodles that contain a lot of calories.

There’s some debate among nutritionists about whether the “negative calorie” idea has merit.  Assigned caloric values are usually nets, meaning the thermic effect of digesting the food has already been subtracted.  On the other hand, some of the calories in plant foods exists in the form of cellulose, which we are unable to digest.

Regardless of the math, though, there’s a valuable takeaway here.  Substituting any of these foods for the much higher-calorie foods most of us eat to get full (bread, crackers, etc.) can have a huge effect on our health and our weight.  Keeping the value of these foods in mind will also help us to order smarter when we eat out or use a delivery service like RushMyFood.com to have restaurant food at home.

The most important thing about these foods is that they’re natural.  True, you can get kelp noodles made with 95% rice and 5% kelp, and you can get pickles packed with sugar.  But you can also get the real foods, and for my money it’s better to lose and manage weight by eating real, fresh, natural foods and exercising than by buying a bunch of supplements that supposedly do the work for you.