It is no secret that a calorie deficit can lead to weight loss – but why is this so? Your ability to gain, lose, or maintain weight involves a fine balance between the energy you put into your body versus the energy that you expend. What goes in includes the foods you eat, and what goes out includes physical activity and your body’s normal day-to-day functions. Disrupting this energy balance, and implementing either a negative or positive energy balance, can cause changes in your weight. This article will discuss the mechanisms of energy balance and how you can apply these principles to your weight loss journey.
To understand energy balance, we must first define calories. A calorie is a unit of measurement that describes energy. Thus, when we talk about energy balance, we are talking about calorie balance. Your energy balance is the relationship between the number of calories you ingest via eating and drinking versus the number of calories you burn during physical activity. Your diet constitutes the energy in, while exercise, movement, and your everyday bodily functions constitute the energy out.
Many consider “energy out” to just be exercise. While working out definitely burns calories, your body also natural burns calories throughout the day, be it by walking, digesting food, or breathing in and out. This is known as your resting metabolic rate (RMR), which is the amount of energy your body expends executing regular bodily functions and maintaining homeostasis (2).
Energy balance is the primary mechanism underlying weight loss, weight gain, and weight maintenance. When your energy in (calories ingested) equals your energy out (calories burned), you will maintain the same weight over time. However, when one of these factors goes up or down, it can cause an imbalance. For example:
Things affecting energy in:
Things affecting energy out:
If your primary goal is weight loss, understanding what goes in and out of your body can help you to meet your goals. For weight loss, you will want to increase the amount of calories out versus the amount of calories going in. This can be achieved by having a negative energy balance via exercising regularly and being in a caloric deficit.
It is important to understand that your energy in and out do not have to be balanced with each day. For weight loss, you will want to average more out than in over time (1).
Depending on your health goals, you may be trying to achieve a positive or negative energy balance. In the instance of weight loss, you will want a negative energy balance. While a negative energy balance will result in weight reduction, it may not always be done in a healthy way. These risks are described below:
Knowing the mechanisms of energy balance, calorie counting might not be enough for weight loss. As there are some risks to having too severe of a negative energy balance, it is important to maintain just a mild negative energy balance for optimal weight loss that is sustainable. To do so, we recommend eating in a calorie deficit with a nutritional surplus. This means eating less calories but eating foods that are nutrient dense. In short: quality over quantity:
Nutrient dense foods contain the recommended daily allowances for essential nutrients, vitamins, and minerals. This involves incorporating foods like lean proteins, vegetables, nuts, seeds, legumes, and whole grains into your diet. Additionally, you should avoid refined and processed foods, especially foods that are high in salt, sugar, and unhealthy fats.
By structuring your diet in this way, you can eat less calories while still being satiated and fueling your body. In addition to adding nutrient dense foods and cutting out harmful ones, we also recommend eating small meals only during an eight to ten-hour window and avoiding skipping meals. This puts the body in a ketogenic state, allowing for optimal fat and weight loss.
In addition to eating a quality diet in a caloric deficit, there are other ways to fuel a healthy negative energy balance. These include:
In conclusion, maintaining a proper energy balance for weight loss is not so black and white. It extends beyond just a calorie deficit, involving a mild negative energy balance that does not adversely affect your health. Individuals must also consider things such as the quality of their food, its nutrient content, the timing of their meals and eating habits, and their physical activity.
