Working Out a Lot Doesn’t Always Increase Your Appetite

During my 28-day body transformation project, I worked out harder than I ever have in my life. Even taking into consideration the potentially wide margin of error in the cardio machines’ calculation of energy expenditure, I estimate that on some days I was burning an excess of 1,000 calories through exercise. On the McDonald’s scale I’m so fond of using, this energy shortfall is equal to the calories found in a Premium Crispy Club Sandwich with medium fries.

During that latter half of that crazy 28-day period, I ate consistently less than I ever have in my life, about 1600-1800 calories per day. The 1600-1800 calories per day wasn’t a range prescribed by my trainer, Ngo Okafor. Calorie counting is emphatically not his bag. It just happens to be the amount of energy contained in three square meals that brimmed with leafy green vegetables, lean meats, fish, and eggs on any given day. Here’s why that figure is so shocking to me: Last year I took an indirect calorimetry test that determined that my body needs 1507 calories of food energy per day to merely exist without losing weight.

The process of breaking down food for energy also consumes energy. Dig this: If I ate 1507 calories and laid in bed all day, I’d need roughly 150 extra calories to exist at the same weight. (The digestion of the food we eat requires around 10 percent of the energy contained in that food to break it down in process known as thermogenesis.) All this to say that 1,657 calories per day is what I’d need to maintain my weight if I finally got around to binge-watching 'The Wire' and literally shat where I ate.

But as I said, in the process of getting me some abs, I was decidedly not doing nothing all day. I walked two miles each way to the gym, ran a sub-8 minute mile on the treadmill when I got there, did a fast paced hour of resistance training then did an hour on the elliptical while re-bingeing Game of Thrones. Additionally, I was walking between three and five miles per day just running my usual errands.

The thing is, aside from one day during which I worked out too much and ate far too little and almost fainted (I didn't make that mistake again), I never once felt hungry or heard my tummy rumble. At some point, wasn’t my body supposed to tell me to start ransacking the fridge or firing up Seamless via hunger pangs?

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This lead me to wonder why I’ve felt far hungrier on days in which I’ve eaten twice the amount of calories and performed very little exercise. Is it the increased amount of protein that’s keeping me sated? The gallons of water I’m drinking? The shrinking of my stomach? I needed answers.

“Your stomach probably didn’t shrink,” says Kimberly Eden Steele, director of the Johns Hopkins Adolescent Bariatric Surgery Program, who knows a thing about shrinking stomachs. Steele explains that while the stomach is stretchy—the average human stomach can hold between one and one and half liters of food—contrary to popular belief, it doesn’t significantly shrink beyond its original size when empty.

The bariatric procedure Steele most often performs—sleeve gastrectomy—reduces the stomach to about the size of a banana. Not only does a smaller stomach hold less food before a patient gets full, it also secretes fewer hunger-signaling hormones to the brain; an effect I’ve apparently managed to take advantage of without going under the knife.

“While eating fewer calories didn’t literally shrink your stomach, reducing your carbs and eating lean protein and fibrous vegetables changed the production of hormones that signal satiety,” she says, offering an explanation for this commonly held notion.

Steele tells me that one of the things she’s looking at in her research is how overeating may be dulling the receptors of dopamine. She hypothesizes that perpetual overeating causes people to eat more to get their hit of this feel-good hormone. “If you can break the vicious cycle of overeating more and more to feel good, you’re going to be satisfied sooner and by foods other than the refined carbs that give you quick energy,” she says.

Steele did confirm that the increased amount of water I’m drinking—well in excess of a gallon most days—is playing a big role in staving off hunger pangs. “When you stretch the stomach by filling it, the organ sends messages to the brain saying that ‘you’re full and you don’t you don’t need to eat any more,’” she says, adding that drinking plenty of water is a tried-and-true method of getting the “shut your pie hole” message up the chain of command.

It’s worth mentioning at this juncture that traditionally, hunger hasn’t been the only thing curing me to put food in my mouth. I’m very prone to cravings for sweets even when I’m totally full. Since I’ve started eating well, however, those cravings have largely dissipated.

New York-based Registered dietitian and nutritionist Stephanie Di Figlia-Peck tells me that filling my plate with lots of vegetables and lean proteins is playing a big role in my cravings for sweets. “Feeling a craving for something sweet is physiological,” she says. I’d always just chalked my sweet tooth up to a simple weakness of character.

She goes on to explain that the primary food source for our brain and central nervous system is glucose and if we’re not getting it because we work through lunch or don’t get around to eating dinner until 10 PM, the brain will send very strong signals to compel you to feed it. “The first thing you’re going to crave is sugar because it’s the preferred fuel source of the brain and central nervous system,” she says.

When I ask her about the idea that, if I'm not eating enough, my body goes into starvation mode and begins to hold on to fat stores like grim death, Di Figlia-Peck explains that while this can happen, it would only be something worth considering if my body mass index (BMI) dropped below the “healthy” or “normal” range of 18.5 to 24.9. I currently have a BMI of 21.3. I’d have to lose a further 20 pounds for my metabolism to hit the panic button.

Interestingly, she wasn’t 100 percent on board with my strategy of purging “bad” foods from my apartment. A healthy food environment isn’t one where non-whole foods are gone completely, but one where bad choices aren’t staring you in the face all the time, she says. This idea has been borne out in several studies including one published in the February 2018 issue of the journal Appetite which asserts that “placing food further away reduces the likelihood of consumption in general population samples.”

Di Figlia-Peck ends our conversation by remarking that my enjoying going to the gym every day is creating a virtuous cycle and setting me up for nutritional success. That stands to reason: If I loathed the long batteries of bicycle crunches and hour-long elliptical machine sessions, coming home to a lunch consisting of a 4-ounce salmon fillet and steamed broccoli would feel like kick in the balls.

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