The Daily Burn

I want to follow up on my most recent post where I discussed the concept of energy balance and how energy intake (calories in) has to be less than energy expenditure (calories burned) in order to lose weight.

First, let’s take a closer look at total daily energy expenditure, or TDEE (calories burned). TDEE consists of four categories, and I’ll briefly touch on each one.

You have probably heard of the first one: basal metabolic rate, or BMR. Your BMR is the total amount of calories (energy) it takes to maintain the basic functions of your body and makes up the majority of your calories burned (around 60-70%). This involves heart rate, breathing, maintaining core body temperature, and the functioning of your organs - basically how much energy you burn while sleeping.

Another component of metabolism is thermic effect of food, or TEF. This is the amount of energy it takes to digest your food and makes up around 10% of calories. Fun fact: protein has the highest thermic effect of food, meaning your body requires more energy to break down protein compared to fats and carbohydrates. This is why increasing your daily protein intake can be helpful for weight loss.

A third component is called non-exercise activity thermogenesis (NEAT). This is all of your activity that is not deliberate exercise and there is huge variation among individuals (10-20% of calories). NEAT includes things like fidgeting, using hand gestures, blinking, pacing, toe tapping, etc.)

And the final component of your metabolism is exercise energy expenditure, or EEE. This only makes up around 5-10% of all of your calories burned during the day. Notice that this is one of the smallest of the contributions toward your total daily energy expenditure.

Most people (myself included) were taught to think about weight loss like this: if you want to lose weight, you should increase your activity and reduce your calories and then attempt to add up the total calorie deficit (assuming you are counting calories) for that day. For example, if you went for a 3 mile run, you might estimate you burned 300 calories. Then you eat in a 400 calorie deficit, and calculate a 700 calorie deficit for that day. In about 5 days, you should have lost one pound (3500 calories). This model is called the “additive energy expenditure model", and recent research has shed some light on why this is not always the case.

Evolutionary anthropologist, Herman Pontzer, published a paper in 2016 (read study here) in which he and his colleagues revised the energy expenditure equation.

The new model, the “constrained energy expenditure model”, reveals that there is more nuance than once thought. To summarize this model, you can think of it this way: the body will try to make your energy intake (calories in) equal to your energy expenditure (calories out) by making adaptations over time.

Your body will make adaptations to sustained changes in the amount of calories you eat or your activity level. If you consistently eat in a deficit, your body will compensate by modifying your BMR, NEAT, TEF, or EEE. For example, Pontzer’s team discovered that the more a person exercises, the fewer calories they burn over time for that same activity. Your body becomes more efficient at that activity level, in order to conserve energy.

As a BMR example, your body may also attempt to save energy in certain metabolic processes by reducing your hormone production, such as dropping testosterone or estrogen production.

In the NEAT category, you may become more sedentary in other parts of the day. You might fidget less, or use fewer hand gestures. Where you would normally stand or pace around, you might start to sit more often.

Another way your body may counter this extra activity is to increase your appetite. Low levels of exercise can help you suppress hunger signals, but the more you ramp up activity, the hungrier you might become in order to compensate for this. If you are not carefully tracking calories, your calorie consumption can easily match or surpass your calories burned for the day.

With all of this information, what are you supposed to do now? For one thing, if you are someone who is tracking calories, stop attempting to track your calories burned for the day. There are no accurate ways to track energy expenditure except in a laboratory setting, such as Pontzer’s. Only keep up with calories consumed, and forget about trying to estimate calories burned.

It is probably safe to say that if you do not have a regular exercise routine, you still need to increase your weekly activity levels. There are hundreds of benefits to regular exercise, but it is a poor strategy for weight loss. Once you have lost weight, it can be a powerful tool to help you maintain the weight that you lost.

If weight loss is your goal, your main focus should always remain on your nutrition. The strategy remains the same - focus on whole foods that are high in fiber and continue to prioritize protein at each meal (remember it has the highest TEF). Limit processed foods because they are less filling (low fiber) and easy to over consume, and they have a low TEF.

The take-away from this is not that exercise is meaningless and you should just eat less - it just helps explain why the process of weight loss is not linear and predictable. For example, it helps us understand why you think you should have lost 10 pounds, but you only lost 5lbs. It’s why you might experience rapid weight loss at first but then plateau after a few weeks. Hopefully this also helps you understand that you should not do a ton of cardio or high intensity exercise classes so you can “burn more calories”.

Strength training at least twice per week, with full-body routines should be a top priority. This will help maintain (and in some cases gain) muscle mass as you lose weight and help you increase your performance in other recreational pursuits.

Aim for a minimum of 30 minutes per day of moderate intensity exercise like walking, jogging, biking, swimming, and yard work.

Walking remains one of the best things you can do for general health and for weight management. 7-8,000 daily steps is a great minimum and there are weight loss benefits going up to the 10-12,000 step range.

Don’t just focus on exercise - create a lifestyle based around activity. Activities like gardening, leisurely hiking, taking the stairs, and grocery shopping in person instead of online accumulate into a large amount of movement throughout the week.

As always, reach out to me if you would like some extra guidance with your nutrition or exercise goals. A lot of people know what to do, but working with a coach helps hold you accountable and to build small habits that result in big changes.