It's that time again, folks. The best time of the year. Thanksgiving, Christmas, and New Years... the holiday season. There's just nothing like it... turkey dinners, Christmas trees, the snow, the gift of giving, the time spent with family. I look forward to it every year. But step inside the psyche of any health-conscious person this time of year, and you may find a war zone:
"I love apple pie, but I don't want any. I don't want it. It goes right to my butt. God, look at it... it's gawking at me. Ahhh okay I'll have a slice. ONE slice. Just one slice and I'll stop. This is the year I keep my weight under control during the holidays. Oh god that was good. Shit girl, give me another. This is better than sex, oh my god. The apple pie god. I love him, he who created apple pie. Screw butt fat, whatever. Men like big butts anyway... they cannot lie."
Right? We all know the holiday season presents a problem. Excessively yummy food + great people + alcohol = weight gain. It happens every year... and come the New Year? Resolutions abound. Gyms explode with new members, we eat less, and we try to right the wrongs of the past few months. But, as anyone who has done this probably knows, that weight doesn't come off with the same ease at which it was put on, and rarely does it stay off.
And that's the point of this post. I want to explain to you why that weight won't stay off, and why, consequently, it's so important to prevent the weight gain to begin with. Saddle up partner...
Body fat set point and the regulation of body weight
In order for this to make sense, we have to first talk about the concept of the "body fat set point". The body fat set point is the idea that our bodies "defend" a certain level of fat on the body. Think about how a thermostat works... if you set the temperature to 70, the system will heat or cool your house accordingly to maintain the temperature at 70 degrees. Our physiology uses a similar system to regulate body fat. If a man overeats one day, his body will adjust accordingly in the following few days by decreasing hunger. In the end, his body weight evens out. The same would be true if he starved himself one day; his body would compensate by increasing hunger in the days to follow. Over the course of a week or two, caloric intake tends to balance out with caloric expenditure (1). Through a system involving the hormone leptin, the brain senses a change in body fat, whether it has lost or gained, and alters hunger accordingly, in an attempt to return to the set point (2).
In the vast majority of us, this system works well. But this all rests on one assumption... that we eat when we're hungry, and we stop eating when we're full. And this is where the problem comes in. In today's society and food environment, it's becoming increasingly difficult to stop eating. We've got access to food wherever we go, it's more palatable than in the past, it comes in larger portion sizes than ever before, and it's advertised to us at every turn. How can we avoid buying a soft, warm, melts-in-your-mouth Cinnabon at the airport when we have an hour to kill and nothing to do but wait?
We can overeat at one meal or on one day without harm, as long as we listen to our hunger cues and compensate later. But overeating without compensation, for any reason, over a period of a few months or more, can be a problem. In overfeeding studies that are designed to induce weight gain, some subjects will return to their normal weight after the study is over, but many do not. Some of the subjects end up hanging on to a little fat, indicating that the body fat set point has increased. This phenomenon has been observed in both animals (3,4) and humans (5,6). Once you establish a higher set point, it becomes extremely difficult to lose that fat. Take, for instance, the fact that when obese people lose body fat, their body goes into a starvation response, despite having plenty more fat to lose (7). Their bodies want that fat.
Back to the holidays...
So how does this relate to the holiday season? Because around the holidays, our food environment takes steroids. We have even MORE delicious treats, MORE palatable food, and MORE drive to eat. Grandma's making you a pie every Tuesday, Christmas cookies permeate the office, there are Christmas parties, there's candy everywhere... it's excessive. Delicious... festive... but excessive.
Given that, this shouldn't be a surprise: According to a recent study, half of annual weight gain in the United States happens during the holidays via voluntary overeating (8). HALF OF IT. And the news nobody wants to hear... people who gain weight during the holidays lose some of it in January, but they hold on to most of it long-term. That's a problem. That means you have a new, higher set point. Your body is now "happy" with more body fat, even if you're not. And once this happens, getting back to the weight you want to be at is made exceedingly more difficult.
We may not gain 20 pounds in one holiday season; according to the study, it's only about a pound on average. But that weight stays on. If you imagine this happening every holiday season for years and years, it's not a stretch to say that you can become overweight or obese from holiday eating alone. All you have to do is overeat for a few months each year. It's likely a major contributor to the obesity epidemic.
Of course, there's a solution hidden in there... don't allow yourself to gain any weight to begin with over the holidays, and you won't have to worry about any of this! It's not easy, but it's better than the alternative if you're trying to avoid gaining weight. For a few good tips on how to accomplish this, check out "3 tips for preventing holiday weight gain" by Chris Kresser.
So try to practice some balance this holiday season. Even though we're already halfway through it (I'm inexcusably late with this post), try to listen to your body. If you want some pie and cookies, have some pie and cookies. But either practice moderation or be in tune to your body's hunger/satiety signals in the days that follow.
Hope this helps you out this year! Happy Holidays!