Calculating Calories for Meal Planning

When it comes to counting calories, people often think of weight loss or management. Although certainly a key tool for weight management, that isn’t the focus here. Calories are key to basic cellular function – or simply stated, they are needed to live and operate. Overall, effective caloric intake best supports your physical, psychological and emotional endurance and health. 

Adequately fuelling your body will keep the bounce in your step while exploring outdoors. When your energy tank is low, on the other hand, you run the risk of mood swings, delayed or altered response or decision making (which cause some risky scenarios)… But frankly, going hungry – when there’s no easy way to get more food – also straight up sucks. Case and point. 

Being aware of how many calories your body needs will help you avoid these concerns, while also helping you feel confident in your meal planning and prep. 

How do you calculate how many calories your body needs?

For starters, basal metabolic rate (BMR) is the base amount of energy – or calories – needed by your body to simply sustain life. Involuntary functions and movements such as breathing, digesting and circulating blood are all part of this. Throw in some physical activities and that caloric dependency or need increases. So how do you know how many calories your body needs? 

Calories needed are determined by cross referencing your BMR with your physical activity expenditure (your base energy/caloric needs and how much energy you burn). This cross reference determines your Estimated Energy Requirement (EER) – also known as Total Daily Energy Expenditure (TDEE). 

Thankfully, some brilliant minds have determined formulas for a person to estimate this. Note that there are a handful of different formulas and approaches out there – and they all will likely provide a slightly different estimate (finding your exact number would require in depth testing and activity expenditure measurements) but they provide a fantastic guideline. 

Tip: If your activity level is expected to vary on a day to day basis (rest days vs intense exercise), mark down the difference between each day to meal plan more accurately. 

Online Calculator

This is ofcourse the easiest tool to use – it does the hard work for you! Plug in your units (and make sure to choose the most accurate activity level for your trip. 

I also like this online calculator because it provides estimates if you were to change your activity level on any given day, and it also outlines your macronutrient needs.  

Ex. Scenario: Myself (28F) wanting to determine my calories needed for a 2 day mountain biking trip (heavy activity) 

Using online calculator = 2787 kcal needed per day 

DIY Formula:

(This method is provided by the Dietary Reference Intakes (DRI) of Canada)

Women : 354 - 6.91 x age + PA x [(9.36 x weight) + (726 x height)] = calories needed per day

Men : 662 - 9.53 x age + PA x [(15.91 x weight) + (539.6 x height)] = calories needed per day

PA = Physical Activity Factor (Factor value chart is posted below)
Weight is to be in kilograms (lbs / 2.2 = kg)
Height is to be in meters (inches / 39.37 = m)

Remember to use PEDMAS to solve: (Parentheses, Exponents, Division, Multiplication, Addition & Subtraction)

Example Scenario:

Myself (28F) wanting to determine my calories needed for a 2 day mountain biking trip (heavy activity) 

Using DIY forumla = 2883 kcal needed per day 

As you can see, when comparing the estimates I used between the online calculator and the DIY formula, the difference is relatively minor at 96 calories.

Do Increases in Altitude Impact Your Caloric Needs?

Yes and no. But leaning much more on the side of no – especially for the average explorer. Studies have shown an increase in metabolism with severe increases of altitude, however, only after several days of exposure. In other words, a person would have to remain in the high altitude area for several days for this to take effect – not be trekking up and back down in a day or 2. 

Keep in mind that people living in higher altitudes are less likely to experience this metabolic change versus those who live at sea level and venture to high altitudes as well – simply because of the drastic change in elevation that the low elevation dwellers experience and need to adapt to. 

If one was to be exploring in high altitudes for several days, however, this is the approximate change in metabolism the body may experience: 

Overall, altitude exposure is not something you typically need to take into consideration calorie needs wise. That being said, the amount of energy required to climb, hike, or bike these intense elevation gains will certainly burn a ton of calories!

Do cold temperatures impact your caloric needs?

There are rumours that exposure to cold temperatures burns more calories. I did some digging to see if this rumour is in fact true. Based on several studies and reports, the general consensus is that exposure to cold weather could cause additional calories to be burned, but is quite modest in most situations. Significant caloric burn only occurs when an individual’s internal/core temperature drops significantly (which is dangerous – more on that below).

To elaborate, when cold, your body will initiate non-shivering heat production to increase and stabilize your temperature. According to an interview between Livestrong and Zac Schlader, an associate professor in the School of Public Health,  this level of heat production will likely only burn an additional 50-100 calories per day. If severely cold, however, to the point of shivering, Schlader says an extra 100 calories per 15 minutes could be burned. 

In other words, the more your body’s temperature decreases, the more calories you burn. That being said, know that shivering is a symptom of mild hypothermia – which is something you certainly want to prevent. 

(*Mild hypothermia is very serious; actions should be taken to prevent the development of full hypothermia. Stopping physical activity, protecting the individual from the elements with additional clothing and shelter, and having them consume emergency calories and water would be advised in this scenario)

Overall, the rumour that exposure to cold temperatures burns more calories is broadly true – but the need to include additional calories in your diet is debatable. As long as your caloric intake is sufficient relative to your needs and activity, and internal temperature decrease is prevented, you’re good to go. 

Knowing how much food to pack for your outdoor adventures starts with knowing how many calories your body needs. To get even more out of your food, learn how to best incorporate macronutrients in your meal plan.

Keep in mind that these approaches are intended to be helpful guidelines when it comes to making an effective meal plan. There’s no need to overwhelm yourself following each guideline to a T – it is completely okay to have some variance.

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The Foodie Behind the Screen

Hi there! I'm Bri.
I create and share nutritious and flavourful recipes for outdoor enthusiasts and adventure seekers.

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