3 Ways Undereating Leads to Weight Gain

Wanting to lose weight is a normal feeling for women in today’s world. We unfortunately live in an age when thinness is seen as overly valuable, and this creates insane pressures for us. We’ve all felt it! We’re constantly bombarded with messages about weight loss, from magazine covers to billboards, even all the way down to the food packaging itself.

Frankly I find this extremely annoying because all the tips and tricks for gimmicky weight loss plans are just plain wrong. The trendy tactics work for maybe a few weeks or months, and then they don’t anymore. Weight loss diets are ineffective, and there are three main reasons why: they alter your hormones to re-wire you to hold on to weight, they lead to reactive binge eating, and they artificially bring you below your body’s weight set point, which leads to easier, faster weight gain.

Now before we dive into the details, I want to reiterate what I hope is already clear on my blog: my goal is not to spread the message that weight loss is of utmost importance. Because it’s definitely not. As women, we are worth so much more than the size and shapes of our bodies, and in the context of eternity, weight is completely meaningless. However, I personally know from experience how awful it feels to be stuck in a pattern of food and diet obsession, battling against your body and feeling out of control. So, if that’s how you feel too, this post is for you.

Let’s dig in!

Slowed Metabolism

You might have heard of the phrase “slowed metabolism” in the weight loss world before. While there are some elements of truth behind the concept, a slowed metabolism isn’t a real thing. “Metabolism” refers to the complex web of chemical reactions taking place in our bodies every second, and it doesn’t have as much to do with weight gain/loss as it gets credit for. However, there are hormonal influences over metabolism, fat retention, and other weight-related processes, and this hormonal balance is extremely sensitive.

Whenever we are chronically undereating (like with dieting), hormonal changes take place, especially with cortisol. Cortisol is the stress hormone, which gets released into our blood stream whenever we have a tough day at work, if we experience a loss, or if we are stuck in traffic, but also when we exercise too much, if we are sick, or if we face other physical stressors. Not getting enough calories on a daily basis (or carbs/fat/protein) raises cortisol levels, and chronically elevated cortisol interferes with the balance of other hormones in our bodies, including those that regulate weight.

One example is thyroid hormone. There’s a delicate web of interactions between cortisol and the thyroid called the hypothalamic-pituitary-thyroid axis (HPT axis for short). Too much cortisol can create a hypothyroid state, meaning thyroid hormone is too low. Hypothyroidism leads to clinical signs of weight gain, low energy, feeling cold, and other signs that we might classically associate with a “slow metabolism.” In effect, undereating leads to high cortisol, which leads to hypothyroidism and weight gain. Other hormones are affected in the same way.

Reactive Binge Eating

A few days ago I accidentally forgot to include carbs in our dinner. I made spaghetti squash with meat sauce, cheese, and a side salad. It looked great on the plate and tasted wonderful, and it didn’t really occur to me in the moment that despite the appearance, spaghetti squash is a vegetable, not a starch. My husband and I enjoyed the meal and then rushed out the door to go to Costco so we could set up our new membership. (My sister and her husband gifted us a Costco membership for Christmas, which is the coolest/funniest thing ever. I love telling people we got Costco for Christmas when they ask!)

Anyway, we started feeling hungry about an hour after dinner, and by the time we got home we were both famished. I’m talking the I-can’t-think-I’m-so-hungry type of famished. So we dumped a bag of tortilla chips on a sheet pan with giant handfuls of cheese, broiled them for a few minutes, and devoured the whole thing.

Ultimately, we ended up eating too many nachos, because we both felt a little sick afterwards. But we were so hungry that our bodies took over all ability to eat mindfully. Undereating at dinner by not including enough calories and carbohydrates led us to reactively overeat in the evening, consuming more food than our bodies really needed and definitely more than we would have eaten had we just remembered to balance our dinner.

Now, because we both eat intuitively, the next day our appetites regulated and leveled off. We didn’t restrict our breakfast to compensate for the nachos or anything like that, but in the past, such a thing would have totally derailed me. I used to binge like that all the time because I’d starve all day, binge eat, and then fall into an endless binge-restrict-cycle. Breaking free of this cycle was fundamental to me finding food freedom.

I also want to point out that occasionally overeating like this isn’t a big deal. It’s a normal part of life. (Think: holidays, parties, etc.) But doing this on a daily basis is a hallmark of an unhealthy relationship with food that probably is causing physical health problems, with weight gain as a symptom.

Falling Below Your Set Point

Initially, undereating leads to weight loss. But eventually, weight stabilizes and we maintain our weight at that too-low energy intake. However this is at a point lower than your body genetically wants to be, and our diets need to be tightly controlled to stay there. When you’re below your weight set point, gaining weight comes very easily. (This is when it may feel like, as folks often say, you “gain weight just from thinking about food.”) At your body’s weight set point, eating slightly more than usual, like a whole pan of nachos, doesn’t lead to weight gain because your body naturally evens things out with changes in your appetite. But when you’re under your set point or have lost weight through extreme restriction, your body wants to gain weight, and takes every opportunity it can to do so. Chronically undereating makes weight gain very easy for your body.

So, what’s the alternative?

Intuitive eating isn’t a diet. The goal isn’t weight loss, or even weight gain. The goal of intuitive eating is allowing your body to do its job of self regulating the process of eating according to hunger and fullness so that you have more brain space for the more important things in life.

If you’re in a pattern of undereating, intuitive eating might cause you to gain weight at first as a consequence of the three factors above. But then if you stick with it, as your hormones balance, your binge eating fades away, and your body learns to trust you again. When this happens, your weight will level out at a healthy number that’s genetically right for you.

There is so much more to life than weight and food, and you deserve the freedom to enjoy it!


4 thoughts on “3 Ways Undereating Leads to Weight Gain

  1. Pingback: PCOS, Explained

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