Some people just can’t stop eating and eating no matter what—and it’s not because they’re hungry. They simply like to eat. If you thought a visit to a psychiatrist or gastric-banding surgeon were the only ways to fix that, hold on. A dietary supplement made from a certain leafy green vegetable may be the answer to curing even the most voracious appetite naturally. But there’s a catch. Not any old green-food supplement will do—and, beware, some green-food supplements are already riding on the coattails of the new product although they may not deliver the promised effect. Here’s the information. You decide.

IT’S NOT EXACTLY THE LEAVES

Before we talk about the new diet supplement, it will help to think about what really makes people overweight. Portion control is often at the top of the list when we talk about weight management, and, sure, we also struggle with food cravings and ways to beat them. But the biggest problem when it comes to keeping a healthy weight is something called hedonic eating. That’s not the same as actually craving a food. It’s “mindless eating,” and it’s often done out of stress or boredom…tends to bring very little pleasure (especially in relation to the calories)…and becomes true gluttony when overdone.

It’s appetite, not hunger.

It turns out that spinach and similar leafy green vegetables, such as kale and collards, can significantly control appetite and, specifically, keep you from reaching for the box of cookies, chips, chocolate covered pretzels or whatever your between-meal edible is. The magic ingredients in spinach and some other greens are thylakoids, which make up the plants’ cell membranes. Rich in vitamins A, E and K and antioxidants, thylakoids include compounds that slow down the digestion of fat…and they impact hormones that affect how the pancreas and intestines trigger appetite, especially hormones that tickle our yens for sweet and fatty foods.

But you would have to eat a pound of spinach (and/or other greens) a day to get its appetite-suppressing effects. Commercially available spinach extracts, which generally are powdered concentrates of spinach leaves, do contain thylakoids and other nutrients, but the new formulation that’s creating the Internet stir about spinach extracts is a powder specifically made from the cell membranes of baby spinach leaves—not the whole leaf…just the part that contains the thylakoids. Called Appethyl, it is standardized to contain specific proportions of the naturally occurring vitamins and other compounds in thylakoids that affect how the pancreas processes fat and affects appetite.

The most recent study using this stuff included 38 volunteers—all overweight women between the ages of 40 and 65—who took part in a three-month experiment. Each volunteer was supplied with a small, two-ounce blueberry smoothie to drink every morning before breakfast. For half of the women, chosen randomly, the smoothies included a teaspoon of the thylakoid extract.

The women were asked to have only three meals a day, not to snack in between meals, and to get at least 30 minutes of low-impact exercise (such as walking) per day. Their weight and blood sugar and cholesterol levels were checked every three weeks, and they were interviewed on the first and last day of the study about their appetites and food and snack preferences.

The results: Cravings, particularly for sweets, were significantly reduced among those who got the extract. Also, weight loss was 43% greater in the women receiving the thylakoid extract than in women whose smoothies did not contain the extract (the placebo group). As far as the participants’ eating patterns, the effect of the supplement kicked in around lunchtime at the beginning of the study and was even more pronounced by the end of the study period—when the effect lasted throughout the entire day. Whereas the women in the placebo-smoothie group craved comfort food—particularly sweets—before lunch and became preoccupied with snacking again after lunch even though they were not hungry, women who had their morning thylakoid supplement did not.

Changes in blood sugar were not dramatically different between the two groups, although blood sugar levels were higher after meals in the placebo group. As for cholesterol, low-density lipoprotein—so-called “bad” cholesterol—was reduced in women receiving the spinach extract, and no impact was seen on high-density lipoprotein (“good” cholesterol). Also, the body’s hormone that suppresses appetite, GP-1, was higher after meals in women receiving the thylakoid extract. No side effects were reported.

Whether whole-leaf spinach extracts, which have been on the market for years, have a similar degree of effect is unknown. They’ve not been put to the test or compared against the thylakoid extract. Although this study and earlier studies, mostly done in animals, of the thylakoid extract were supported by noncommercial academic and government sources and conducted by researchers from Lund University in Sweden, the lead researcher is affiliated with the commercial research group that developed and is now beginning to market the thylakoid extract.

All in all, this study is extremely promising for those who want to lose weight or who seem to have to work hard to maintain their weight. Although Appethyl in its pure form is now available only in Scandinavia, it is currently being sold in the United States as one of many ingredients in an appetite suppressant called Hydroxycut Appetite Control Plus Appethyl. The manufacturer doesn’t say how much Appethyl is in each serving, however.