Originally posted by Michelle at The Fat Nutritionist | Published: AUGUST 11, 2015

Much of the feedback I receive on the blog, and in comments I read on social media share similar themes. Rather than perpetuate misinformation, I approached a trusted registered dietitian in my hometown for some facts. If you’re in the market for a dietitian who can “take you from anxious and messed-up around food to chill and pretty happy,” contact Michelle here.

I’ve cut my portions to 1/2 of what I would usually eat (or) I’m trying to stay at 1200 calories a day but I’m soooo hungry!

Of course you’re hungry! You’re eating less than you need, and your body is poking you, trying to get you to eat more.

1200 calories a day is not enough food for most grown-up people.* Unless you’re simply a small, not-very-hungry person (ballpark: 4′ 10″ and 100 lbs.), you’re very likely not eating enough to support your needs.

When it comes to energy and appetite, your body attempts to match your energy intake to your energy expenditure. That means, if you use a lot of energy one day, running around more than usual, you will be hungrier afterward, as your body attempts to make up the deficit. I’ve even experienced “catch up” hunger several days removed from the event.

But the biggest chunk of your energy expenditure comes not from activity, but from existing and continuing to exist, and that depends a lot on how big you are. Bigger people tend to expend more energy just being alive, and therefore, they’re going to need to eat more in order to match their intake to their expenditure. Your body is remarkably accurate at doing this, and research shows a very narrow margin of error in matching intake to expenditure over very long periods of time, for most people. This results in a mostly-stable weight for years at a time.

It’s true that many people’s weights will slowly drift upward over years and decades, but from a survival perspective, your body sees that as less risky than if it were to drift downward. Some people experience dramatic weight instability, gaining and losing lots of weight, sometimes unintentionally, in relatively short periods of time. If there’s no underlying medical issue (like an illness, or a thyroid problem, or a medication interaction), it may be that their eating and/or activity has been chaotic enough to disrupt the body’s usual balancing act.

But, back to your question: if you’re purposely eating fewer calories than you expend, you will feel hungry and your body will attempt to get you to eat more. Sometimes using very sneaky means…like “Ooops a box of cookies!” or “I accidentally the whole pizza.” Your resting energy expenditure might also tank, as your body tries to conserve energy. You’ll be sleepier, less active, and less able to warm yourself up in the cold. And when the weight loss inevitably slows, or you begin regaining weight, you will blame yourself and your lack of willpower, instead of the true culprit: an energy deficit and your body’s clever survival mechanisms.

If long-term research on diet has taught us anything, it’s that most people’s bodies do not like being in negative energy balance — the state required to lose weight — for very long.

People can and do suppress their hunger by focusing intently on their diet, but as soon as their attention wavers — say, they get sick, or they get really busy at work, or some family comes to visit — it is almost inevitable that they will go back to eating more. Often, more than they would have if they hadn’t been restricting. And if their attention never wavers, there’s a chance they’ve triggered an underlying eating disorder.

Ignoring one’s hunger signals requires enormous effort, and I’m not convinced that for people who do it successfully, it’s always a good thing. In the case of an eating disorder, it’s definitely not.

If you’re on a calorie restriction diet, you have two options: you can continue restricting and just put up with the hunger (and the binges and weight regain that will almost certainly follow), or you can decide that your body’s hunger signals are not wrong, are not aberrations, and are, in fact, worth listening to and respecting. You can decide that you have the right to eat what you need, not go hungry, and to weigh what your body prefers…and that you can still improve your health and body image, if you want to, even if your weight never changes.

This does not mean that you must follow every single impulse toward food, because every single impulse toward food is also not respecting your hunger. Most of us are surrounded by hundreds of food cues every day, in the form of advertising, and it makes us think of food even when we’re not otherwise hungry. But you can commit to learning what hunger truly feels like, and then deciding, when it calls, that you will answer it by feeding yourself matter-of-factly and well.

Responding to your hunger appropriately will give you the best chance for long-term weight stability. If you were previously eating more than your body wanted or needed, responding to your hunger might even help you settle at a slightly lower weight. Bonus: it will also provide you with the energy you need to support exercising, running around with your kids, doing hard physical labour, or whatever your life requires. Physical activity will, in turn, further contribute to a stable weight, as well as more energy (and, hopefully, fun) in the moment, and better long-term health.

In my opinion, that’s a much better deal than giving yourself less than you need.

*But there are always exceptions and outliers, and some people naturally eat very little. Energy needs are also very different for hospitalized people, or people with medical conditions that affect their resting energy expenditure.

Related: How can I lose weight if I can’t eat healthy foods?