While we would all like to think that the key to weight loss is simply “calories in vs. calories out,” in reality, it’s much more complicated than that. Restrictive fad diets and modalities would like us to believe otherwise with their overly simplistic, black-and-white rules. But the truth is, successful weight loss cannot be done using a quick-fix or one-size-fits-all mindset. We need to consider the complexity of the body’s metabolism and our physiological response to hunger to fully understand what is going on and approach weight loss in a way that’s healthy and practical.
What Happens When We’re Eating Enough?
To start off, let’s define metabolism. According to Merriam-Webster, metabolism is defined as “the chemical changes in living cells by which energy is provided for vital processes and activities, and new material is assimilated.” So essentially, metabolism is how we convert food to energy in order to fuel the necessary processes to survive. I would like to point out that one’s metabolism is not stagnant. Based on certain circumstances, such as availability of food, amount of physical activity, and various environmental factors, one’s metabolism can increase or decrease. This is important to keep in mind when we consider calorie restriction.
Under normal circumstances when we eat a meal, our body breaks down food throughout the digestive tract, absorbing the parts that we need (such as macro- and micronutrients) and excreting the parts that we don’t, along with other metabolic by-products. The nutrients that we absorb are shipped off to various parts of the body where they can be used for energy or stored for future use. When we are eating an adequate amount, our body is expecting a consistent influx of energy. Therefore, we are able to fuel bodily processes at a normal rate and digest, absorb, and utilize our food efficiently.
What Happens When We Restrict Too Much?
When we aren’t eating enough, our body goes into a fasted state, and eventually a state of starvation, because the body starts to anticipate a calorie deficit for the foreseeable future. In a state of starvation, the metabolism slows down dramatically in an effort to conserve what energy we have. Our rate of digestion decreases and our body starts to utilize available energy stores to make up for the lack of energy coming in.
While many people assume this would ultimately result in fat loss, the first thing to be used in this situation is muscle mass. Only after a prolonged period of starvation, once most of the muscle mass is gone, will the body switch to fat stores for energy, in an effort to preserve what little muscle is left. This loss of muscle mass slows down our metabolic rate even more. The more muscle we have, the more calories our body uses while at rest, so we are burning more calories throughout the day. Therefore, when we lose muscle, our energy expenditure goes down and our calorie needs are lower.
All of this is basically your body compensating for the lack of calories coming in. Therefore, if your goal is to lose weight, it is definitely in your best interest to eat a healthy amount of calories, rather than severely restricting in an effort to decrease the calories in/calories out ratio. You’ll really end up doing exactly the opposite.
An Alternative Way to Lose Weight
So I’ve discussed what we should not be doing when trying to lose weight. But what does it look like to eat a healthy amount of calories in order to properly fuel your body and promote weight loss? Obviously, if you are a healthy adult with a relatively normal metabolism, a certain degree of calorie restriction is usually necessary for weight loss, depending on your lifestyle and activity level. But it is important to stay away from diets that suggests any less than 1200 calories per day, no matter your age, sex, height, weight, or activity level. Any less than 1200 calories is simply not enough to sustain any adult without resulting in muscle loss and a decrease in metabolic rate. To determine what your calorie goal should be, you can use apps such as MyFitnessPal, or see a dietitian for a more personalized approach.
While counting calories can sometimes be more harmful than helpful, there are situations in which it is necessary, especially if your satiety cues are a little out of practice. If you’re just starting your weight loss journey and don’t feel very familiar with the amount of calories in certain foods, you may want to consider counting your calories to make sure you don’t go too far over your daily calorie goal.
Another beneficial practice for losing weight is to focus on nutrients. Nutrient-dense foods generally tend to be lower in calories. So if your focus is on getting enough fruits, vegetables, whole grains, and lean proteins, your calorie count will naturally go down as well. Along those lines, it’s always a good idea to get a variety of foods in your diet. Do not cut out entire food groups. I repeat, DO NOT cut out entire food groups. While it can be tempting to set a bunch of rigid rules to lose weight, this is almost never successful and often cuts out many essential nutrients that the body needs to function. Instead, try to get a little bit of everything, with a focus on nutrient dense options.
Ok I know there was kind of a lot to process in this post. But hopefully it helps you understand why severely restricting calories can actually hinder your weight loss rather than help it. Changing over to a healthy lifestyle doesn’t have to (and shouldn’t) be a rigid, miserable process. Be sure you’re properly fueling your body so you can reach your goals!