Connection Between Serotonin and Appetite: How to Suppress Cravings

Do you find yourself eating mindlessly or shoving cookies into your mouth every chance you get? According to Judith J. Wurtman, author of The Serotonin Power Diet, it doesn’t have to be that way. Here, she offers her opinions and tips on how to eat to turn off your hunger.

Q: What role does serotonin play in how and what we eat?

A: It plays an extremely important role. The most important and overlooked thing is that serotonin will shut off your appetite. When it’s working properly, it makes you feel satisfied. You can eat less food than you would like to eat, and you can decrease your portion sizes if you need to lose weight, but triggering serotonin will make you feel full. My co-author, Nina T. Frusztajer, and I use this example all the time: You go to a restaurant for dinner, and you’re very hungry, and while you’re waiting for dinner to be served, you munch on some bread and a little salad. Twenty minutes go by before your dinner arrives and when it finally does you say, “Gee, I’m not hungry anymore.” It’s not from the roll or the bit of lettuce, it’s because once you digested those carbohydrates your brain makes new serotonin and sends a message that you’re not that hungry. It’s a natural appetite suppressant.

Second, serotonin also has a function in regulating mood, and antidepressants tend to activate serotonin. In the afternoon, when you are feeling a slight drop in your motivation, focus and emotional well-being, it’s due to a daily drop of serotonin around 4 pm. Many people experience this subtly, but others feel it more strongly and they often feel an intense craving for carbohydrates. They’re not hungry, and they may have eaten lunch recently, but they reach for the cookies because of a signal from their brain that tells them to make new serotonin. When you eat carbohydrates, your brain can make more serotonin, then your mood and focus are restored and you’ll feel less irritable.

Q: What does the Serotonin Power Diet look like?

A: We know there are people who are carbohydrate cravers, and those who tend to seek carbohydrates when they’re stressed; these are the emotional overeaters. Then there’s another group of people who aren’t able to turn off their eating, even when they’ve had enough; these tend to be people who are on antidepressants. Both of these groups are experiencing a serotonin malfunction. For the emotional eaters, serotonin is being used up by stress, so the signal from the brain is to keep eating — which would be OK, except that people usually eat the wrong kinds of carbohydrates and they’re getting too many calories from ice cream or french fries. And then we have people who are on antidepressants and they eat a meal and can then forget that they ate. Even though their stomach is full of food, their brain can’t communicate that he/she’s satisfied. And I think these are the two main causes of obesity.

The point of our diet is to make sure that the brain makes enough serotonin to turn off eating, even when there are drugs (like antidepressants) that are making you eat too much. And second, to make sure that you always have enough serotonin in your brain to immunize yourself against stress. So then when you are stressed, you won’t suddenly find yourself throwing food into your mouth impulsively because there will be enough serotonin there to calm yourself down.

The way to do this is incredibly simple. What we know from research is that in order for your brain to make new serotonin, you eat a certain, therapeutic amount of carbohydrates. It goes from potato to insulin to an amino acid called tryptophan to serotonin. And once the serotonin is made, you get a feeling of satisfaction, you’re not hungry anymore, and you also feel better.

Q: So timing is really key to this diet?

A: Yes. Timing is important to make sure you’re making serotonin at times of the day or evening when you may feel more stressed, or when you feel more like eating. For example, it’s not really important to make serotonin when you first wake up in the morning. At that point, it’s more important to get nutrients into you. We suggest in our book that you have a serotonin-producing snack about an hour before lunch. This way, you produce enough serotonin so that you’ll be happy with your chicken and salad. Then, since the afternoon is universal carbohydrate craving time as serotonin drops, have another snack — but instead of a fat-filled chocolate cookie, have rice cakes or pretzels or a low-fat breakfast cereal. You don’t want to tantalize your taste buds, you just want to produce more serotonin. It’s not a treat; it’s a treatment. Then, if you’re the kind of person who tends to overeat at night — and a lot of people do — have the kind of dinner that’s going to produce more serotonin, and that’s a dinner without protein.

Q: Are there certain types of foods that are particularly helpful when it comes to boosting or regulating serotonin?

A: Any carbohydrate other than fruit, because insulin is not released after you eat fruit. But think of all of the carbohydrates people eat all over the world — potatoes, bread and cereal grains, pasta and rice. They’re all fine and will help turn off your appetite. People obviously eat when they’re not hungry, so this isn’t foolproof. Even when you’ve had a big dinner, if someone brings out a chocolate cake you’re going to have a piece. But we’re talking about people who need to have their willpower helped. What you have to do is get people to say, “I don’t really feel like having that so no, thank you.” The feeling you get when you’ve got enough serotonin is similar to the feeling you get when you drink water and you’re not thirsty anymore. You feel like you’ve had enough.

Q: And, just to be clear, you’re not advocating that people ditch fruit entirely and simply load up on bread and pasta to help them lose weight; instead, you advocate using small amounts of non-fruit carbs as appetite-suppressing teasers to a meal for people who have trouble controlling their appetite and weight?

A: Yes. Our diet pushes vegetables; up to two cups for lunch and for dinner. We do limit fruit because most tend not to have the concentration of nutrients that vegetables do and they tend to be higher in calories. Also, we do not want people to think fruit is without calories. But our diet has a strict schedule of consuming “therapeutic” amounts of carbohydrate to increase serotonin production. We insist on one snack an hour before lunch, one in the afternoon an hour before dinner and for the first two weeks of the diet, another in the mid-to late evening. By doing this, we get serotonin levels boosted and then the dieter doesn’t not have to worry too much about will power. The serotonin will take care of controlling the appetite and so adherence to a diet is easier.