For those of you who do not understand the role of energy balance, we will talk about it here. Calories matter despite what you have heard from many diet magazines. Calories are a measurement unit of energy. A calorie (kilocalorie) is the amount of energy required to heat up one kilogram of water one degree Celsius. The potential energy in food and the energy burned by our bodies is measured in calories. Every food we consume is made of calories. Any activity performed by the body, including important processes such as breathing, digestion, and the beating of our hearts, burns calories. Depending on your activity level and how much you eat, three things can happen: 1. You eat the same amount of calories that you burn. That’s when your weight remains the same. Most people over a long period of time tend to maintain this equilibrium unconsciously. 2. If you consume more calories than your body can burn, you may see a steady weight gain. This surplus in calories can be converted into fat and/or muscle (if you’re resistance training, surplus calories will help fuel muscle to grow). 3. If you consume less calories than your body can burn, you may experience fat loss but not necessarily steady weight loss. The deficit in calories will force your body to tap into its own fat reserves for energy. Depending on the level of calorie deficit, how much time you spend working out, and the macronutrients you eat, the body will get the extra energy from burning fat and/or muscle. For most readers this concept is not a new thing. But the majority might not understand the role of energy balance because most diet books rarely discuss this topic. Some of the popular methods for losing weight include going on low carbohydrate or fat intake diets, eating only at certain times of the day, fasting for days, or so called “clean eating,” which is the total removal of certain foods based on arbitrary reasons. These methods still have to adhere to the laws of thermodynamics because weight loss or weight gain always depends on the total calorie intake. Authors and fitness instructors have good intentions creating all these rules, but it is not those rules that work. Any diet works when it creates a calorie deficit. What they hope is that people will eat less because they have to follow a specific set of rules. They know many people would like to follow simple black and white rules, which would indirectly create a calorie deficit, and in that calorie deficit you lose weight. Some of the popular rules: 1.Do more cardio so you burn more calories, which will result in an energy deficit, leading to weight loss 2.Do not eat after 6 p.m. so that you consume fewer calories, which will result in an energy deficit, leading to weight loss 3.Eat only “clean foods” so you consume fewer calories, which will result in an energy deficit, leading to weight loss 4.Do not eat carbohydrates so you consume fewer calories, which will result in an energy deficit, leading to weight loss 5.Be conscious about eating fewer calories, which will result in an energy deficit, leading to weight loss All those methods stated actually could lead to the same result: weight loss. Indirectly restricting your calorie intake for weight loss in order to lose fat is not a bad thing, but the question is, is that method sustainable? If you want to achieve an advanced physique or optimize your nutrition you should have a basic understanding on the cause of weight change. If you don’t learn about the basic energy balance you might confuse those methods I mentioned above as an optimal approach. Many folks do follow these kinds of diets and achieve good results. For instance, if your friend is made to believe that eating clean is the only way to lose fat, she will not understand why it is possible to hit a plateau, or that when she does hit that plateau (as when weight remains the same for a while), she will have no idea why and may not know how to adjust her calorie intake. Your friend cannot just say “I’m going to eat much cleaner than the current clean food I’m eating” and lose more weight. This same scenario applies to people who believe that cardio is all they need in order to lose fat. Before working with me, I had clients who ran hours per day but still reached weight loss plateaus, despite all their exercise, because they did not know that they also had to restrict their calorie intake. So far we have discussed weight loss in order to lose fat, but the total energy intake is just as important when you are trying to gain weight. Muscle growth is dependent mostly on maintenance and a calorie surplus which will lead to weight gain. An energy surplus means that you eat more calories than the body burns at the current weight and activity level. Complete beginners do experience gaining lean muscle mass even when eating maintenance calories or sometimes even in a calorie deficit. This is what we call newbie gain effects. Especially young adults that are still growing can experience newbie gains. When most people say they would love to put on some weight I always assume that they want to gain muscle and not fat. Muscle gain, unlike fat gain, is a slow process and it does not usually require a large calorie surplus. Eating too much when you are trying to maintain your weight or gain muscle mass will lead to more nutrients than the body requires for creating muscle tissue and this excess will be converted into fat. Because of this, it is important to calculate the correct number of extra calories you need to gain muscle without gaining fat. Some of my clients told me that before they started training with me, they attempted to bulk up but ended up gaining too much fat. That’s exactly what happens when you consume more calories than the body needs, which is likely when you do not monitor your intake. That’s why I also think it is important to have control of my clients’ training volume (or at least if they’re training with other trainers then I always request for the plan so I have an idea of their energy expenditure). When people say they would love to lose weight I always assume that they mean fat and not muscle. In order to achieve this, strict attention should be given to the macronutrient composition of the diet and not just focus on calories. Macronutrients, which are also called macros, are the protein, fat, and carbohydrates that make up the food we eat. Losing body weight does not necessarily mean that your body composition, which is the ratio between fat and muscle, is better than it was before. Something to keep in mind is that rapid loss of body weight is not always a good thing. This is because when the body loses weight too quickly, it sheds muscle tissue along with body fat. When we lose weight we want to maintain or gain our muscle mass and work not to lose it. We can achieve that by eating a proper diet with the correct amount of macronutrients, exercising, and calculating the most optimal amount of calories or calorie deficit that we need to stay strong.