There has been some confusion lately regarding BMI, BMR, and TDEE.
What on earth do all these crazy acronyms mean and how can they help you with your weight loss goals?
Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women. BMI is a good gauge of your risk for diseases that can occur with more body fat. The higher your BMI, the higher your risk for heart disease, high blood pressure, type 2 diabetes, gallstones, breathing problems, and certain cancers.
Although BMI can be used for most men and women, it does have some limitations:
- It may overestimate body fat in athletes and others who have a muscular build.
- It may underestimate body fat in older persons and others who have lost muscle.
For a “normal” healthy person, BMI is an accurate tool in assessing health and disease risk.
Basal Metabolic Rate (BMR) represents the number of calories your body burns at rest (Essentially, what you would burn if you laid around in bed all day.) You need calories to carry out normal body functions like respiration, cardiac function, and digestion. The healthier you are and the more active you are the higher this number will be. Lean muscle mass will also increase your BMR. Train More = Eat More.
Never base any dietary decision on the number the BMR calculator spits out.
You want to remain above this calorie count at all times. When you dip below your BMR (as most women do) you are actually starving your body. You will halt all weight loss and your body will retain as much fat as possible to “keep you alive.” Eat, please. 🙂
I recommend the IIFYM BMR calculator if you are interested in knowing your BMR. It’s the best one I’ve seen online (taking into account age, height, weight, and activity level.)
Your TDEE (Total Daily Energy Expenditure) is the amount of calories your body burns in a 24 hour period, sleeping, working, exercising, playing and even digesting food. This is the amount of food you need to eat to maintain your current weight given your activity level, age, height, weight, and gender.
Again, I recommend the IIFYM TDEE calculator is you are interested in knowing your TDEE.
So How Do You Lose Weight?
You lose weight through having a calorie deficit. Simply put, a calorie deficit is eating less than your body needs to maintain itself and thus creating a deficit.
Your “sweet spot” for weight loss is about 500 calories less than your TDEE. Once you deduct 500 calories from your TDEE, you can use that number for your personal weight loss goals.
- BMR = 1,400
- TDEE = 2,100
- 2,100-500 = 1,600
- 1,600 calories per day is needed for healthy weight loss for this particular individual
1,600 calories can be filled many ways. Just because you are hitting a particular caloric goal does not mean you will get the body composition you are looking for. Macronutrients (carbs, proteins, fats) are important parts of a healthy, balanced diet.
If you are a sedentary individual who does not engage in any type of physical activity, there is no need for you to consume a large amount of carbohydrates. However, neglecting a food group is not advisable either. Carbs are necessary for optimal functioning of your body, and the gray matter in your brain utilizes carbs for fuel. A break down of 30% carbs, 40% protein, 30% fats would be a good way to go.
If you are active and your goal is to crush some weights at the gym or perform sports at a higher level, aim at 35% carbs, 40% protein, 25% fats.
Remember, these are suggestions and guidelines. Every person is different. Some people do really well with high protein, low carb while others function well with high fat. If you are interested in personalized nutrition, you can find that here.