How does a person figure out how many calories they are supposed to eat? I faced this in the process of losing weight and now am trying to figure it out in maintenance. There are so many initials being thrown about and so many different theories - it's enough to make you head spin!
Let's see, we have BMI, BMR, RMR, TDEE, and then all of those have variants - AHHH!!! And then there's the 2 big debates that practically make people kill each other on the internet - "Starvation mode" and "should you eat back you exercise calories"? Let me try to break some of this down - as in what worked for me - and see if it helps anyone figure out how much they should be eating!
- BMI stands for Body Mass Index. It is a range of what is considered a healthy weight for a person's height. BMI was originally used to calculate trends in large populations. It has a lot of weaknesses for calculating an INDIVIDUAL'S healthiness. For example a body builder will have extremely low body fat and be very healthy, but have a large muscle mass and can fall into the overweight or even obese category. However, it can give you an idea of where you should be. For my height, a healthy weight falls between 98 and 132 pounds. At 118, I am at a 22.3 BMI, solidly in the middle of what is considered healthy.
- BMR and RMR - These are really the same 2 things. They stand for Basal Metabolic Rate and Resting Metabolic Rate. Basically this calculates how many calories you would burn if you laid in bed all day. It takes into account your height, weight and age. Men burn more - rat bastards. The more you weigh the more you burn, as well. There are different calculators out there and you're bound to find a difference based on different calculators. Mine tends to range between 1,150 and 1,250. Which SUCKS - makes me want to fall on the floor and throw a temper tantrum. Why? Because I LIKE TO EAT. Again, there are some weaknesses in these generic calculators, especially if you are working out - I'm going to talk a lot more about that tomorrow so stay tuned.
- TDEE - Total Daily Energy Expenditure - This is a useful tool, especially if you work out. It calculates not just what your body burns on a daily basis, but what your calorie needs are based on your activity level. This online one is the best IMO: http://www.iifym.com/tdee-calculator. It really tries to break down what you do in a day and how much that burns. Most TDEE calculators put me at 2,000 calories per day to maintain my weight.
If you are on a site like myfitnesspal, it takes a lot of this into account and gives you the amount that you should be eating a day in order to lose weight. I find their calculations very low and limiting. It almost always gives women, especially short women like me, 1200 per day. For many of us, that is just too low.
How much should you be aiming to lose in a week? Well, that depends how heavy you are. Remember, 1 pound is around 3500 calories. So to lose 1 pound per week, you should have a deficit of around 500 calories a day - that is, you are burning 500 calories more then you are eating. 1-2 pounds per week is the healthy way to do it. You can go a little higher if you are very heavy and will have to aim for a little less as you get closer to your goal weight.
- Should you eat back you exercise calories? NO!! Now, if you are a heavy exerciser, like I am, you should eat more. But NEVER rely on machines to calculate how many calories you just burned. They are notoriously inaccurate. Heart rate monitors with a chest strap are more accurate, but still way too imprecise to use. I ran 11.25 miles today and my heart rate monitor says that I burned over 900 calories. There is NO WAY I am going to eat an extra 900 calories today. But I will eat a couple hundred over my normal intake. I am trying to listen to my body and if I'm hungry, I eat. If you are a light exerciser, I would not feel bad about having a small snack, maybe like a light yogurt - under 100 calories if you are hungry.
- Starvation mode - In all practicality it doesn't exist. If you eat less then 1200 calories per day a couple days in a row, you aren't going to immediately screw up your body forever. Having said that - 1200 calories is pretty low and you should not aim to go under that. Losing weight should be a slow, steady process if you want it to be life-long. There are no quick fixes. Slow and steady wins the war on fat. And if you eat too low for too long of a term, you will completely fuck up your metabolism. Signs that this is happening? Extreme fatigue all the time, difficulty concentrating, hair falling out, mouth sores, period stopping - if you have these, you should see a doctor and start upping your calories.
- Macros - Some people worry about how many grams of protein, carbs, fats, sodium they eat. If you want advice on that, you'll have to look elsewhere, sorry. In general, I believe everything in moderation. I aim to eat a lot of protein, a reasonable amount of complex carbs, add in some good fats - if you are eating like you are supposed to - meaning fresh fruits and veggies, lean meats, the macros will take care of themselves. If you are skipping your fruit so that you can have an ice cream sandwich and fit it into your calories tonight? Well, that's not healthy and you are probably not within your macros.
- The dreaded plateau - At some point in your journey, you are going to hit the dreaded plateau. A true plateau is NOT going 3 days weighing the same. It is going a few weeks of doing what you are supposed to and weighing the same. This generally means that your body has adjusted to what you are doing and needs a shock to the system to get things moving. I hit 3 plateaus during my journey and they sucked. You need to shake things up. Often this means upping your calories and adjusting your workout routine. That's what worked for me!
All of this can be incredibly confusing and frustrating. First off, do what I didn't do and wish I had - TAKE MEASUREMENTS! Sometimes your weight will remain the same, but you will go down in inches. That's a good thing. Use calorie counters, BMR, TDEE calculations to give you an idea, but don't hold them as gospel. Everyone's body is different.
And finally, the best advice is the simplest! EAT RIGHT AND EXERCISE. If you are doing this, your WILL hit your goal!