The What, Why and How of a Calorie Deficit
A calorie deficit occurs when the body’s intake of calories is less than its expenditure. Maintaining a calorie deficit over time results in weight loss as the person would effectively be consuming less calories than they need to maintain their weight. Hence, maintaining a calorie deficit has proven itself as a sustainable method of weight loss.
Calorie deficits can be created by reducing intake of calories, getting more exercise or a combination of both. But it isn’t possible to create an effective strategy without having some basis for it. This is where your Total Daily Energy Expenditure (TDEE) comes in. You can calculate it manually or using a TDEE calculator.
Start by finding your basal metabolic rate (BMR), which represents the amount of calories that the body burns while undertaking the basic bodily functions. Once you get this figure, multiply it by a factor that corresponds to your physical activity level. This gives you your TDEE. Your actual TDEE may vary based on your genes or body composition as well as your activity on a given day, but this number gives a close enough estimate of how much you actually need to consume.
The next step is to decide how much of a calorie deficit you want. Most people aim for a deficit of about 500 calories per day. This means a net intake of 500 calories less than your TDEE. A healthy range for the deficit is 500-1200 calories per day for women and 500-1500 calories per day for men. If your maintenance calories are low to begin with, it’s advisable to not to have a calorie deficit at all. After you set your calorie deficit goal, it’s time to make some changes.
It is much easier and much more sustainable to figure out ways to reduce your calorie intake in a day than it is to figure out how to burn more. So let’s start with your diet.
When cleaning up your diet, opt to pay attention to the gram amount of protein, carbohydrates and fats you consume as opposed to the calories. These are what the body derives its energy from and so they are required in large amounts. Hence they are called macronutrients. While calories provide your body with energy, the nature of the macronutrients they are derived from are all different and have different effects on your body, so each of them have to be consumed in different proportions. Proteins are 4 calories a gram and help in muscle building. Carbohydrates are also 4 calories a gram and are the body’s preferred source of energy. Fats are 9 calories a gram and contribute to the body’s energy reserves. As long as you keep your intake within the amounts you set for yourself, it doesn’t really matter what you eat. Just be careful not to have an overambitious calorie deficit goal.
Conquering food takes care of most of your calorie-related problems, but you still need something to bolster the effects of the deficit. That’s where exercise comes into play.
A good rule of thumb is 30 minutes of aerobic exercise, at least 3-4 days a week. Aerobic exercise generally comprises everyday movements such as walking or running and also activities like dancing, which makes it easy to integrate into daily life. If you want to be more intentional with exercise, you could carve out a block of time in your day dedicated to it.
Aerobic exercise is not a foolproof solution though. While in a calorie deficit, the body burns without distinguishing between lean muscle mass and fat. This results in loss of muscle mass and lowers your BMR, which accounts for most of the calories you burn. Thus, it is important to try to maintain your muscle mass and even gain some more of it as well. This can be combated through adding resistance training to your exercise schedule, While it won’t result in as big of a calorie expenditure in an individual session, this will result in muscle building and an increase your BMR.
You will have to keep revising your caloric deficit goal as your maintenance calories keep changing at each new weight. Consistency is key. You cannot get the results you desire without sticking by your strategies for the long term. It’s okay to fail as long as you pick yourself up again. As clichéd as it sounds, weight loss is a marathon, not a sprint.
Sridhar Iyer
SY BSc.