Friday, January 18, 2013

"How many calories should I eat to lose weight?"

One of the biggest things I learned on my weight loss journey was that you need to eat in order to lose weight. This went against everything I had always believed about weight loss, so it made me nervous to accept this information. Yet, when I finally did let it sink in and took the leap of faith to follow through with the plan, the weight really did start to come off. Not only that, it started to come off in regular increments. I was shocked. For YEARS, I assumed that women should consume 1200-1500 calories per day while trying to "diet". That always stuck in my head, so that was my go-to plan whenever I wanted to lose weight. For YEARS, that never worked for me. Now I know why! So whenever people ask me about weight loss, one of the first things I like to focus on is your BMR.

"BMR? What's that?" -- is the common response. That was my response, too, when I first heard of this.

BMR stands for "basal metabolic rate". It is one of the first pieces of information you need to determine, before you can figure out how many calories you need per day. Your BMR is the amount of calories your body burns on a daily basis, just while keeping you alive. Imagine yourself as a vegetable, laying in bed all day not moving. Your BMR is the amount of calories you would need to consume to stay alive in that condition. Your calorite total for the day should never, ever be below your BMR. Why? If you aren't giving yourself enough fuel to even cover the calories you burn without even moving, you are going to be essentially starving your body. Your body will then click over to "starvation mode". Your body notices the lack of calories and as a self-defense mechanism, it slows your metabolism. It wants to try to conserve as many calories as it can since it's not getting enough. Thus, weight loss becomes much more difficult since your body is slowing your metabolism -- your ability to burn calories. This will only work against you.

(I've included a link in the summary at the end of this blog where you can determine your BMR.)

Obviously, we are not laying in bed all day not moving. So, the BMR is a baseline number that helps you to determine how much you should eat in a day, but it is not the whole picture. Your body burns calories all day long: as you work, as you run errands, as you clean your house, etc. You're constantly burning. So, you need to be eating your BMR calories PLUS you need to eat additional calories to fuel your normal daily activities. Now, your activity each day can totally vary. So when you determine your activity calories, this is only an estimation.

To figure out your daily activity calories, you can use the Harris Benedict formula. This is not an exact science, but it can be a great estimation to get you started. Here is the Harris Benedict formula (you need to know your BMR to do this calculation):

Harris Benedict Formula
To determine your total daily calorie needs, multiply your BMR by the appropriate activity factor, as follows:

•If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2

•If you are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375

•If you are moderatetely active (moderate exercise/sports 3-5 days/week) : Calorie-Calculation = BMR x 1.55

•If you are very active (hard exercise/sports 6-7 days a week) : Calorie-Calculation = BMR x 1.725

•If you are extra active (very hard exercise/sports & physical job or 2x training) : Calorie-Calculation = BMR x 1.9

As you can see from the descriptions, the Harris-Benedict formula INCLUDES your workout calories. Some people (such as myself) choose not to do it this way. I only consider my normal routine NOT including exericse.

Why do some people choose to leave out exercise calories? Well, some people (such as myself) use heart rate monitors to get much more accurate information about calorie burning during workouts. I would track my burned calories in a much more specific way, so I did not want to use the estimated numbers. Plus, my workouts would vary week-by-week, so I did not want to have to keep adjusting my calorie counts if I had an easier or harder workout week.

Another reason some people don't include exercise calories is because some calorie-counting websites, such as, ask for users to consider the information separately. Their calorie determination is based on your normal daily activity WITHOUT considering exercise. If you sign up for, in your settings, you will be asked to choose from:

Sedentary: Spend most of the day sitting (e.g. bank teller, desk job)

Lightly Active: Spend a good part of the day on your feet (e.g. teacher, salesman)

Active: Spend a good part of the day doing some physical activity (e.g. waitress, mailman)

Very Active: Spend most of the day doing heavy physical activity (e.g. bike messenger, carpenter)

Then will generate a calorie goal for you based on your BMR and your daily activity NOT INCLUDING EXERCISE. Any time you work out, you get to add those burned calories to your daily total. Yes, that's right. You get to EAT MORE when you workout. It's excellent motivation. Trust me.

"So, how do you lose weight then?"

Well, this is where additional math seeps in. These calorie estimations all tell you how much you are supposed to be eating on a daily basis, if you were not trying to lose weight. But, if you're trying to lose weight, you do need a little bit of a deficit. You shouldn't be dropping to 1200 calories, which was commonly assumed (especially by women). But you do need to lower your calories.

Here's the quick math:
3500 calories = 1 pound
If you want to lose 1lb per week, you need to lower your WEEKLY total by 3500.
3500/7 days = 500 calories per day
You would need to drop your daily total by 500 calories per day to lose 1lb per week.

Let's use my information for example:

When I first started to learn about calorie counting, I was about 165lbs. Using a BMR calculator (I will include a link at the end for that), my information was as follows:

5'9", 31 years old, 165lbs
My BMR = 1551.35

So, I should not be eating less than 1551 calories per day. (Now do you see why those 1200 calorie diets would NOT work for me? I was starving my body!) This is what I would need just to lay in bed all day without moving.

Now, outside of working out, I am really not all that physically active. I wouldn't call myself sedentary (I do have 3 kids!), but I am typically doing light cleaning/chores and running the kids around to activities. I will use the Harris Benedict Equation:

BMR x 1.375 (for lightly active) =
1551 x 1.375 = about 2133 calories

That means if I wanted to maintain my weight, I would need to eat 2133 calories per day. Now, if I wanted to lose 1lb per week, I would subtract out 500 from my daily total so that I could create a weekly deficit of 3500 calories:

2133 - 500 = 1632 calories

So, WITHOUT EXERCISING, I would get to eat 1632 calories per day to lose 1lb per week. Again, this is a lot more than the 1200 calories I was sticking to while trying (unsuccessfully) to lose weight in the past. Plus, it gets better! If you don't include your workout calories in that total, you actually get to eat those additiona calories, too.

Let's say I worked out for 60 minutes and my heart rate monitor tells me that I burned 600 calories for that hour. That means my daily total will be:

1632 + 600 = 2232 calories

Yes, you read that right. A whopping 2232 calories and I would STILL be set up to lose 1lb after a week.

This was a hard pill to swallow, for me. Mentally, I was always under the impression that I would need to eat LESS in order to lose weight. So, the idea of eating 2200 calories in a day AND losing weight was just not something I had faith in. Since I tried so many other options and failed, I decided to take the leap and give this a shot. Shockingly, it worked. It is NOT an exact science. Just because you SHOULD lose 1lb per week does not mean you WILL. There are many other factors: types of exercise, amount of exercise, types of foods eaten, age, metabolism, etc. But this is a great place to get yourself started.

Now let's take my same information and see what says:

If I tell that I am 5'9", 31 years old, 165lbs with a lightly active lifestyle and the goal is to lose 1lb per week, MyFitnessPal tells me I should eat:

1560 calories per day

That is a mere 72 calories off from the estimation I got using the Harris Benedict Formula. Essentially they are the same. DOES expect you to input your burned calories from exercise, though. If you are going to go this route, I HIGHLY recommend getting yourself a heart rate monitor that will track your burned calories so you get a much more accurate reading. The MyFitnessPal system does have estimations you can use when inputting your exercise; however, often they are much higher than what you would have actually burned. The only way to know for sure is to use a heart rate monitor. (Even those are not exact, but they are MUCH more exact than the estimations.) Also, do NOT rely on those heart rate monitor handles and calorie burn counts on the machines. They are NOT accurate.

Don't have a heart rate monitor or the means to get one?

That's OK. You can actually use the Harris-Benedict Equation to determine your calories WITH your exercise included. If I were to use my information from when I had started with calorie counting for weight loss, I would choose the following from the Harris-Benedict Equation:

"If you are very active (hard exercise/sports 6-7 days a week) : Calorie-Calculation = BMR x 1.725"

Calories = 1551 x 1.725 = 2675 calories - 500 calories for 1lb loss = 2175 calories

I was working out 6-7 days per week doing 60-90 minute workouts. Because of that, I would have chosen the "very active" listing. This means my calorie goal would be 2675 per day MINUS the 500 calories for a 1lb loss per week, so 2175. See how close that is to MyFitnessPal's estimation plus my heart rate monitor total equaling 2232?

It can also be beneficial to create a range for yourself if your activity tends to vary. If I use the same BMR and use the "moderately active" formula, I get a total of:

Calories = 1551 x 1.55 = 2404 calories - 500 calories for 1lb loss = 1904 calories

I could try to stick between 1904-2175 calories, depending on how rigorous my workouts were for the week, and still aim for a 1lb loss per week.

Now, to review:

1) You need to determine your BMR (basal metabolic rate) as a way to figure out what your daily caloric needs will be. To determine your BMR, you can visit the following website:

2) You need to add in your daily activity calories either by using the Harris Benedict Formula or by using a website like to come up with your calorie total.
- Decide whether or not you will INCLUDE exercise calories into your daily activity estimation.
- If you want to add on exercise calories later, consider only your normal daily activity, outside of exercise.
- If you want to add on exercise calories later, I highly recommend using a heart rate monitor to accurately determine what you are burning.
- If you WILL include exercise into your daily activity calories, be sure to choose 2-3 of the activity labels (lightly active, moderately active, very active) to create a RANGE of calories that would be appropriate depending on how hard you are working out.

3) For a 1lb loss per week, you will need to subtract 500 calories from your daily total, since 3500 calories = 1lb.
- Remember, already deducts the weight loss calories for you. Only subtract these calories if you are just using the Harris Benedict equation to determine your caloric needs.

4) Never, ever go below your BMR or you will slow your metabolism and make losing weight really difficult.

5) This is NOT an exact science. These are purely estimations. Results WILL vary from person-to-person since every body has different needs and so many other factors play into weight loss. Also, do not expect immediate results. It can take time for your body to adjust to dietary changes.

**It is important to consult with a doctor before starting a new weight loss or diet program to be sure it is safe for you and your medical needs. Remember, I am not a doctor. I am simply sharing the weight loss information I have learned. You may want to consider doing additional research of your own on these topics for additional scientific information. This was meant to be a general overview.

No comments:

Post a Comment