By definition, maintenance calories describe the amount of food that you need to maintain your body weight.
When you calculate your calorie needs on any website or talk to many nutrition experts out there, you will get one number that is considered your “maintenance” set point. Eat more than this set point and you should expect to gain weight. Less than that set point and you should expect to lose weight. It’s pretty simple.
However, in practice that is not always what we see. If you have ever tried a very moderate calorie change of say, 80 calories per day, you probably noticed that not much happened. We see this with our clients very often.
We know that the purpose of our metabolism is to adjust to changes in our environment. This includes changes in our food environment and intake. When we lower our intake, a number of things can happen. We fidget and move around less. Maybe you stop tapping your foot while you sit. Stop moving your hands when you talk. Little things you don’t even notice stop happening as your body tries to conserve energy. As you decrease your intake, you absorb and use more of the calories you eat. Eating less means less energy required for digestion of your food. As you decrease your energy intake, you down-regulate production of certain hormones such as T3 that impact your motivation for exercise. Now these things don’t make a HUGE difference in your energy requirements, but they do lower your needs by a small percentage.
The opposite happens when we increase intake. Our NEAT increases, we move around and fidget more. We absorb less of what we eat. Our digestion requires more energy. Energy and motivation for training increases. All of these things effectively INCREASE our calorie needs per day.
We see this manifest in a few different ways. Often, we encourage our clients to increase their intake, especially if they have performance goals. The goal with many athletes is to increase intake as much as they can tolerate without weight gain. Maybe we have someone who has been on a deficit for a long time and we want to reverse diet them for a period of time. Often after much debate, we increase intake by several hundred calories per day and see no change on the scale. This happens as your body up-regulates many processes that increase your daily energy burn. Alternatively, when we drop calories, we do not see an immediate response on the scale. The same thing is happening but in reverse. The down-regulation of metabolic processes lowers daily energy burn.
What this means that if your goal is to gain or lose weight, you might have to push outside of your maintenance range in order to make that happen. If you have increased calories by 200 per day above your maintenance set point and are seeing no change, then that 200 calorie increase has become your new maintenance set point from which you should work off of.
Metabolic adaption is a very normal, perfectly natural response to changes in your daily intake. Everybody is different and the extent to which your body will “buffer” or “flex” into your calorie intake will be different than your friend or partner. Your body might respond differently to a calorie surplus versus a calorie deficit. It might take a week or two (or four) to start seeing changes. What is important is to find what works for you and your current goals and stick to it.
When we discuss dieting to achieve goals, we are always making certain assumptions that are important to address before beginning any nutrition program. The first assumption is that intake is being measured accurately. When dealing with small deficits or surpluses of 200-300 calories per day, accuracy becomes important. We aren’t saying you have to weigh and measure everything forever, but it’s a very good tool when making initial changes to intake levels.
The second is that the person is in a healthy state to make changes to their intake. We never recommend prolonged calorie deficits. If you are stalled and not seeing results in a calorie deficit after a long period of time, decreasing calories further is not likely to be the answer. The same thing applies for a calorie surplus although with less deleterious effects. The act of eating tends to be very inflammatory and increasing intake indefinitely comes with it’s own set of problems. Our recommendation is always to stick with a calorie deficit or surplus for 4-8 weeks before returning to a maintenance range for a period of time. There are more advanced techniques that can be used to mitigate the metabolic adaptation that occurs over the course of a deficit or surplus, but those exist outside of the scope of this article.