In 2009, researchers recruited men and women who were classified as “obese” and put them on an extremely low calorie diet. For ten weeks, these men and women ate around 500 calories by consuming medical shakes and lost on average 30 pounds. After the initial 10 week period, they discontinued the shakes and engaged in nutritional counseling. Despite the significant weight loss and coaching, the participants regained 11 pounds after a year and most interestingly, reported increased feelings of hunger and a pre-occupation with food and eating. Biological testing on these participants revealed that the hormones in their body that controlled hunger was about 20 percent higher than at the beginning of the study. The researchers concluded that the body had “a coordinated defense mechanism with multiple components all directed toward making [the participants] put on weight.”[1] In other words, even if you lose significant weight on a low calorie diet, your body has defense mechanisms to make you return to your original weight.
If you have ever tried to lose weight, then you have definitely been told the old adage to “eat fewer calories” while simultaneously “burning more calories through exercise or activity” if you want to be successful at losing weight. This is what scientists and researchers refer to as the energy balance equation. If you are in a negative energy balance, then you will lose weight because you are burning more calories than the body requires. If you are in a positive energy balance, then you will gain weight because you are consuming more calories than your body requires. Simple, right?
Before we continue, let me stop you for a second. I am not going to suggest that the BeginnerPaleo diet allows you to eat an unlimited amount of food so long as it is the “right” food. This would be doing you a disservice. Consuming an unlimited amount of calories of any type of food will ultimately result in weight gain. What I am suggesting is that weight gain and weight loss is more abundantly more complex than simply “balancing your calories.”
Recent research into the lives of hunter gatherers has shown that the current obesity crisis facing America is not due to a lack of exercise but rather the over-consumption of certain types of energy dense foods.[2] The takeaway from these types of studies is that people seeking to lose weight should focus less on exercise and more on nutrition. In effect, the Paleo Diet does just that by forcing you to consume foods that have the proper combinations of fats, proteins and carbohydrates. If you are overweight, then this will naturally cause you to lose fat and gain muscle.
In its most simple form, a calorie is the amount of energy or heat required to raise 1 gram of water 1 degree Celsius. The energy balance equation was derived by researchers and scientists and are a result of the first rule of thermodynamics. In its simplest form, the first rule of thermodynamics tells us that energy in must equal energy out. Most diets cling to the energy balance equation like an accountant would his balance sheet. If you add calories to the diet, without taking them away through exercise or activity, then your body will hold on to those calories and you will gain weight. The process is linear. Calories in must equal calories out.
In this section, I will examine 3 common problems with the “energy balance” equation and then review the real reason why you gain weight and how the Paleo Diet can fix the problem.
A Closer Examination of the Typical Energy Balance Equation: The Magical Number 3500
You have probably heard of the “energy balance” equation to lose and maintain weight. It goes something like this:
- A pound of fat contains 3500 calories.
- To lose a pound of fat, you must create a negative energy balance (calories in must be less than calories out) of 3500 calories. That is, you must burn 3500 calories more than you consume to lose weight.
- There are 7 days in a week. To lose a pound of fat a week, you need to keep your calorie intake the same and burn 500 calories per day.
- To determine what exercises burn 500 calories per day, go to an online calculator (Google “activity calculator”) and see how long you need to work out each day to burn 500 calories.
- Repeat every day until you are at your goal weight.
- Once you reach your goal weight, you need to determine how many calories to consume each day to maintain that goal weight.
- If you consume more calories than what is required to maintain that goal weight, you have to exercise a certain amount to “burn” those excess calories.
- Repeat until dead.
Problem #1: The Energy Balance Equation is Usually Wrong
To see why the calculation above is more complex than at first glance, let’s look at an example. A 45 year old man currently weighs 200 pounds and his goal weight is 175 pounds. Thus, he has 25 pounds to lose. Using the math above 25 pounds times 3500 calories per pound of fat equals 87,500 calories he needs to burn. If he burns 500 calories per day through exercise and keeps his diet the same, then he should have that 87,500 extra calories burned off in 175 days!
What activities can he do that burn 500 calories? According to the online activity calculators, if he runs at 5 mile per hour for 40 minutes, he will burn 500 calories. If he runs for 40 minutes each day for 175 straight days, he will have lost 175 pounds.
Simple right? Wrong!
What all activity calculators and the calories burned equation above ignore is that people burn calories by doing nothing at all. This is referred to as your Resting Metabolic Rate (RMR for short). Your RMR is what keeps you alive every day – you burn calories to keep up with required bodily functions like breathing, brain functions and even processing the food that you eat. RMR is generally calculated over a period of 24 hour hours and gives you a baseline reading for how many calories you need just to stay alive.
For our 45 year old male who weighs 200 pounds, his RMR is 1,924 calories. That is, if he did nothing all day, he would still burn 1,924 calories or about 1.34 calories every minute.
This affects our exercise calculation above – remember that we determined that if he runs for 40 minutes he will have burned that magical 500 calories right? However, this calculation does not take into account his RMR. Had he not gone out for that run at 5 miles per hour and sat in front of the TV he would have still burned 54 calories. His “net burn” (the calories over and above his RMR) that he expended on his 40 minute run is actually 446 calories. Taking into effect his RMR, he would actually have to run for 47 minutes to have a “net burn” of 500 calories.
And it gets worse. As he continues to run day after day, our sample guy will hopefully lose weight. How does the calculation change when he now weighs 190 pounds? At this point he will now burn have to run 44 minutes to burn that 500 calories. His RMR has actually decreased to about 1,860 calories per day or about 1.29 calories every minute. To have a “net burn” (calories burned over RMR) of 500 calories, he will now have to run for almost 50 minutes!
And when he reaches that magical 175 pounds, he will have to run for almost 1 hour at 5 miles per hour to have a “net burn” of 500 calories!
Aside from all of the math above, what the calories burned calculations fail to take into account is your specifics. The numbers that are given by all activity calculators are generally based on an average of a large sample size – they don’t take into account your specific genetic makeup or any of the factors that would affect how you burn calories or what you require to function in the real world.
Problem #2: The Energy Balance Equation Can Easily Be Undone by One Small Slip from Your Diet
The focus of Beginner Paleo is to give you the best bang for your buck.
Assume for a second that our sample male does take into account his RMR when he determines the level of activity he needs to have a “net burn” of 500 calories. The first day, he straps on his running shoes and heads out to run for an hour – he chose an hour of exercise just to be on the safe side. We will also assume for a second that our overweight guy can actually run for 1 hour.
What happens when he comes home from running for an hour? He will probably be tired, sweaty and most likely . . . hungry!
And when you feel hungry, your body tells you to eat!
The math of the “energy balance equation” tells us that eating after exercise is the quickest path to undo the calories burned during exercise. Consuming 16 ounces of a sports drink (100 calories) and an energy bar (250 calories) after exercise will easily add back in 350 calories.
And the scary part is how quickly and easily those calories burned can be consumed. What took an hour to burn can easily be undone in a couple of minutes.
Multiple scientific studies have concluded that an increase in physical activity will increase our appetite.[3] This is because the body works hard to stay in energy balance. To put it simply, your body will try to keep the amount of energy you expend equal to the amount of energy you take in. Think about your own experience. How do you generally feel after a long workout? Do you feel more or less hungry? You probably have a larger appetite after you exercise than before.
What the “calories burned” equation assumes is that you are able to simultaneously increase the number of calories burned through exercise without increasing the number of calories you consume. We readily accept that you can exercise for an hour per day without working up an appetite and succumbing to undoing all of that hard work through eating additional calories. In fact, most studies show the opposite – you will increase the number of calories you consume in response to how much you exercise and how many calories you expend.
Problem #3: The Energy Balance Equation Cannot Be Correct Over the Long Haul
Based on the energy balance equation discussed above, weight gained and lost throughout your life is determined by the number of calories you consume and burn. You must balance your calories exactly throughout your entire life or you will gain weight. If you step on the scale one morning and find that you have gained a few pounds, the thinking is that you will skip a few snacks or exercise a little bit more.
In the incredible book, “Why We Get Fat: And What to Do About It” by Gary Taubes, the author looked at the significance of twenty calories per day. Based on the energy balance equation set forth above, he calculated that by simply overeating by twenty calories per day, you would gain two pounds of excess fat per year. Repeating this process for 25 years would result in a net fat gain of 50 pounds! As he noted in the book:
Twenty calories is less than a single bite of a McDonald’s hamburger or a croissant. It’s less than two ounces of Coke or Pepsi or the typical beer. Less than three potato chips. Maybe three small bites of an apple. In short, not very much at all.
Twenty calories is less than 1 percent of the daily caloric intake that the U.S. National Academy of Sciences has recommended for a middle-aged woman whose idea of regular physical activity is cooking and sewing; it’s less than half a percent of the daily quota of calories recommended for an equally sedentary middle-aged man. That it’s such an insignificant amount is what makes it so telling about the calories-in/calories-out idea. If what’s necessary “to maintain weight,” as the National Institutes of Health says, is to “balance the energy we eat with the energy we use,” then consuming an average of twenty calories a day more than you expend, according to the logic of calories-in/calories-out, will eventually make you obese.[4]
Mr. Taubes then asked the simple question: if some men and women stay at the same weight for their entire lives, how is it possible that they are capable of maintaining perfect energy balance the entire time? Matching calories in with calories out to within one percent requires “an exactness . . . which is equaled by few mechanical devices.”[5] And if slipping off the diet by one single bite will throw off the calorie in/calories out equation over a lifetime, then what causes us to lose weight and maintain that weight loss?
[1] http://www.nytimes.com/2012/01/01/magazine/tara-parker-pope-fat-trap.html?pagewanted=all&_r=0
[2] http://www.medicalnewstoday.com/articles/248333.php
[3] http://well.blogs.nytimes.com/2013/01/17/the-appetite-workout/
[4] Taubes, Gary (2010-12-28). Why We Get Fat: And What to Do About It (p. 58). Knopf. Kindle Edition.
[5] Taubes, Gary (2010-12-28). Why We Get Fat: And What to Do About It (p. 60). Knopf. Kindle Edition.