Calculating Calories Per Day

Determining Caloric Needs

On many of the mom blogs/facebook sites I follow, one question that I see arising quite frequently is “How do you maintain your milk supply while losing weight?” Another question in this topic I also see is “What method do you use to try and lose weight?”

As I have said before, I think the best method of losing weight is simply, diet and exercise. This coming from my health/exercise science and nursing degrees. Yes there are other methods out there, and they may work for you. However, I am just going to talk about what I do, which is diet and exercise.

First and foremost, DIET. UGH… that ugly, four letter, curse word. Right?! WRONG! As I have discussed before I strictly calorie count and give myself 1-2 cheat meals per week (usually on the weekend). But how many calories should you eat per day?

Many programs and apps can work great for calorie counting and logging. If you type in your age, weight, gender and height, they may also provide you with a daily calorie limit. However, be weary, those sites simply use an equation but can often times be robotic. What I mean by this is that they use a formula to calculate your daily calorie count and how much to decrease your intake by to lose weight. However, they may not take into consideration your BMR and the minimum that you need per day. There is actually a point where going too low in your daily intake becomes harmful, and if you go past that point, you might actually retain weight.

One of the better ways to determine your calorie count is to use the Mifflin St. Jeor equation. This equation helps determine your BMR (Basal Metabolic Rate). That’s fancy lingo for the minimum amount of calories your body needs for essential functions like breathing, digesting, etc. (aka to stay alive). This is a number you should never go under.   

Men
10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) + 5
Women
10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) – 161.

To determine your weight in kilograms take your weight in pounds and divide it by 2.2

To determine your height in centimeters take your height in inches and multiply by 2.54

Example:

A 130 pound (59kg), 5’8” (172cm), 29 year old, female

[10 x 59] + [6.25 x 172] – [5 x 29] – 161

590 + 1076 – 145 – 161

1360 calories/day.

So as you can see, per the example, that individual should not eat less than 1360 calories per day. This is the minimum number that she would need to maintain her bodily functions. This number is presuming you basically sit on a couch all day and do nothing but breathe! Hehe. This doesn’t include the amount of calories burned walking around, doing chores, exercising, or producing breast milk.

If you play around with the numbers, you can see that as you age and lose weight, your body needs less calories per day. That is because as we age our metabolic rate decreases naturally. When you lose weight, there is less of “you” (i.e. fat) that your body has to maintain, thus decreasing your basal metabolic rate.

Total Calories Per Day

To determine how many calories you need per day including exercise/physical activity, you will need to multiply your BMR by your physical activity level (see chart below). This is just an estimate based on average physical activity level. When trying to determine what category you are in, be honest with yourself. If you over estimate or under estimate, then you might not see the appropriate results. 

Lifestyle	Description	Multiplier
Sedentary	Little to no regular exercise	1.2
Mild Activity	Exercise for at least 20 minutes, 1-3x per week. (ex. Bicycling, jogging, basketball, swimming, etc). Also includes no exercise but a busy lifestyle that requires frequent walking for long periods.	1.375
Moderate Activity	Exercise for at least 30-60 minutes, 3-4x per week.	1.55
Heavy (Labor Intensive) Activity	Exercise for 60 minutes or greater 5-7x per week. Labor intensive jobs also qualify for this level (i.e. brick laying, carpentry, construction work, farming, landscaping, etc).	1.7
Extreme Activity	Exceedingly active or demanding activities such as marathon training, multiple daily training sessions, assembly line jobs. Note: this level of activity is very difficult to achieve and highly unlikely for the general population.	1.9

Let’s use the same girl from the above example. Let’s presume that she exercises for about 60 minutes 3-4 times per week and on the days she doesn’t workout, she has a fairly laborious job where she walks 3-4 miles during her workday. She would probably qualify under “moderate activity” using the chart from above.

If we used her total calories earlier (1360) and multiplied them by 1.55 (moderate activity), then we would get 2108. So this female needs about 2100 calories per day to MAINTAIN her weight. This number does not include calories from breastfeeding/milk production.

Breastfeeding Caloric Needs:
To continue this example above and presuming the individual breastfeeds, one would need to add in the additional calories burned from producing milk. This equates to about 20 calories per ounce of milk produced. For those who exclusively pump (like myself) the amount of calories is super easy to figure out. I simply multiply my daily total pumped (usually around 50 ounces) by 20. This number equates to about 1000 calories (for me) burned from breastmilk production.

For those who actually breastfeed from the boob, the way to determine caloric needs is a little more difficult. Some individuals will say “breast feeding is about 300-400 calories more per day.” This may be true, but if you have an over-supply, twins to feed, or your baby just consumes a lot more than the average baby, your production may be higher than 20 ounces per day. The best way to determine how many ounces is by weighing your baby pre and post feed using a baby scale. This type of scale can convert to ounces. By subtracting your pre from your post, you can see what your baby actually consumed. You could do this for every feed or just do it once and then multiply by how many feeds per day baby has (more of an estimate). [Note: make sure you weigh after a good feed, rather than just a snack].

Once you determine this number, you need to add it to your total activity that you previously calculated. So for the female above, let’s say she also produces 50 ounces of breastmilk per day, she would need to eat 2100 (daily total) + 1000 calories (breast milk). That’s about 2360 calories per day. That’s a lot of calories just to maintain your weight!

For those of you who are dieting and breastfeeding and wondering why your supply isn’t being maintained, check out how many calories you are eating per day. If you are trying to lose weight and cutting your calories significantly, then your body may not be getting enough food to make the milk your babe needs!

SUMMING IT UP

1.  Figure out your BMR
2. Use your BMR and multiply it with your daily activity level  
3. Add in calories from breast feeding.

The number you get is an estimate that you need to eat to maintain your weight!

Stay Tuned for more information on creating a calorie deficit, to help lose weight!