My long time great friend and Sensei, Jamey recently asked me “how long do I need to be exercising before I start losing fat?” Jamey had read an article indicating that exercising for a specific amount of time, I think it was at the 12 minute mark your body would switch to “fat burning mode”. I’ve heard this question asked several different ways over the years and even contemplated it myself. The answer is, and nobody wants to hear this is, “it depends”. Rather than go down the rabbit hole of why “it depends” let me attempt to shine some light on what the real question is. Jamey is an incredibly busy dude, as most of us are. He has a demanding career, a large dynamic family and runs a martial arts school. Jamey is super busy and wants to make the most of his time. I believe the real question most all of us want to know is “I want to lose weight, what is the best use of my time and effort?”
Let’s start with why we accumulated the excess “fat” in the first place.
As humans, storing energy is our job and we are damn good at it. Our bodies are the ultimate storage machines. Being super efficient at storing energy is one of the biggest reasons we’ve made it this far! More than 99% of the time that we have been on this planet, in our current evolutionary form, we have needed to store energy to survive. With the exception of the last 100-150 years, going back hundreds of thousands of years, food has been scarce, most of the time. Almost always it was feast or famine. Honestly, according to today’s standards, it was famine the overwhelming majority of the time, not a constant feast like we have now. “Back in the day” we did not have a never ending availability of food. We had to hunt, gather, farm or fish and sometimes the food just wasn’t there. So when food was available our bodies did all we could to save as much as possible. That’s what we are built for. When there was no food available we had to rely on the energy that we had stored in our bodies to get through the day.
The Calorie Hypothesis
Most all personal trainers, nutritionists, registered dietitians and doctors will say the reason we gain weight is that we take in more calories than we burn. That’s just not true. The next time someone tells you this, ask them how that works. You’ll probably get an answer like ‘that’s just how it works’. Why? because they don’t know. They will not be able to explain to you how this works because there is no hormone or enzyme or molecule that takes extra calories and stores them as fat on the human body. The human body does not count anything, let alone calories. There is no calorie counting gene or cell or molecule. The idea of calories in-calories out has been around for so long that it’s become dogma.
The reason that the calorie in-calorie out hypothesis is wrong is because it’s based on physics and not biology. Using physics to explain biology just doesn’t work.
What is a calorie? A calorie is the amount of energy that would need to be burned to raise 1 gram of water 1 degree Celsius. A calorie is not an actual “thing” it is a unit of measurement. When you burn calories you are simply increasing you bodies core temperature and heating up the water in your body. This has nothing directly to do with using or storing fat.
Breakdown of calories in macro nutrients:
- Carbohydrate = 4 kcal per gram
- Protein = 4 kcal per gram
- Fat = 9 kcal per gram
- Ethanol (Automobile fuel or drinking alcohol) = 7 kcal per gram
Breakdown of calories in alternative fuels:
- Kerosene = 11 kcal per gram
- Hydrogen Gas = 34 kcal per gram
Lets think about something for a minute. Skinny Jenny doesn’t want to be skinny anymore. Skinny Jenny wants to get fat. All Jenny would have to do is consume copious amounts of kerosene and hydrogen, right? Of course not. That would kill her. Why? Because Jenny’s body is a biological organism not a machine. The human body runs on biological pathways and not physics.
The same would be true if Heavy Harvey wanted to lighten up a bit. If Heavy Harvey would just eat less “calories” than he burns Harvey would begin to lose weight, right? Using the units of measurement from above, if Harvey ate 100 less calories per day than he consumed would Harvey lose 11.1 grams of fat, 25 grams of protein, 25 grams of carbohydrate, 2.9 grams of hydrogen or 9 grams of kerosene per day?.. See how ridiculous this sounds.
Instead of applying the calorie hypothesis to human weight gain or loss, let’s think about the types of fuels that our bodies use to make energy. There are two primary sources of fuel our biologically complicated human bodies use to make energy or store it. Glucose, which typically comes from carbohydrate rich foods and fat which we either eat or make. We are almost always in either the process of storing fuel or using fuel to make energy.
Insulin – The Bully Hormone
After consuming a meal or a snack or a soda etc. insulin is secreted from the pancreas and jumps to action. The presence of glucose in the blood and to a lesser extent, amino acids (proteins), initiates the flow of insulin. One of the primary jobs of insulin is signaling cells to uptake glucose, and insulin is relentless. Insulin will continuously work on the receptor cells in muscles and organs like the liver until the almost all of the glucose has been taken up by these cells and stored as glycogen or stored as fat in adipose or fat cells. A typical, healthy individual has about 50 times more fat stores than glycogen. In addition to being relentless in trying to get the glucose stored, while it is present, inulin prevents the mobilization of stored fat. When we are constantly fed, meaning we are not giving our bodies a break from food, we stay in a state of hyperinsulinemia. Besides being in a continuous state of attempting to get things put away, when we have high levels of insulin for continued periods of time our cells become insulin resistant. Insulin resistance makes it more difficult to get the glucose stored and the pancreas works harder to produce more insulin. The higher level of insulin prevents the mobilization of stored fat and glycogen. The the continuous high levels of insulin fans the flames of insulin resistance causing storage of the glucose more difficult creating a viscous cycle of higher glucose and higher insulin levels in the blood.
I want to lose weight, what is the best use of my time and effort?
According to a study from 2019, 88% of Americans are metabolically unhealthy. This means that 88% of Americans have some level of insulin resistance, most don’t know.
The four biggest moves you can make to start becoming more insulin sensitive are:
- Time restricted eating also know as Intermittent Fasting
- Reduce or eliminate processed carbohydrate and sugar
- Eliminate seed oils such as soybean, canola, corn and cottonseed oils
- Build muscle
Becoming more insulin sensitive is essential in becoming a fat burner or hybrid fuel burner (fat and glucose) rather than mostly glucose. Become more insulin sensitive, workout fasted occasionally and you will get the most out of your time in the gym.
It Depends
Depending on your level of insulin resistance, how much you glucose you have stored and how much glucose you have drifting around in your blood directly determines how quickly your body starts using fat for energy when exercising. So yeah, Jamey. It depends. Hope this helps.
Jim Nutter
A Little Harder To Kill 