It might surprise to some to think of being a fat runner. At one time, I thought running was the fastest way to get in shape.
When my youngest son started school, I thought it was time I got fit. Indeed if I ran a marathon, I would lose the baby weight I gained with my sons.
Running a marathon with a charity endurance training program seemed the best way to get in shape. I will be thin by the time of race day. But that isn’t what happened, and I was a little fatter when I ran the 26.2 miles.

I was not the only fat runner
I am not alone, and it isn’t hard to notice that about half the people at the start line are overweight. It isn’t only running events that you might notice. There are quite a few fat runners at the start line. Look at the start lines of triathlons and bike rides too. If you are an overweight athlete, you may be frustrated because you already know this.
Training for the marathon didn’t help me become thin but I found I enjoyed endurance sports. Training was fun and I made friends with many fellow athletes. I went on to work for the charity program I trained with. I saw hundreds of runners go thought the program. Many fellow athletes, especially women, were fat runners. A Danish study from 1989 study sought to answer the question, does running help you lose weight. The study included took 18 months to train a small group of sedentary people. The study consisted of 18 men and nine women to run a marathon.
By race day, the men had lost an average of five pounds. For the women “no change in body composition was observed,” the researchers write. “This idea that you’re going to run a marathon and the pounds are going to melt away is not realistic,” one of the researchers said. She’s currently coaching a group of high-school runners. She and her co-director have a sad little joke: “You train for the marathon, and then you do the weight-loss program afterward.”
No one wants to be a fat runner.

You might be wondering, why don’t runners lose weight. Some of it is likely due to the advice given to runners. The idea that exercise is the key to weight loss and carbohydrates are needed for performance. In an editorial scientist argue that diet is more important than exercise.
In the BMJ editorial, the authors highlight that there are many health benefits to exercise, but weight loss is not one of them. “Regular physical activity reduces the risk of developing cardiovascular disease, type 2 diabetes, dementia and some cancers by at least 30%,” they write. “However, physical activity does not promote weight loss.”
The evidence that diet matters more than exercise is overwhelming. You can exercise until the cows come home but still be fat if you are eating a poor diet. All the sugar and carbs pushed on endurance athletes contribute to the battle of the bulge. Eating excess carbohydrates can make even normal weight athletes unhealthy.
We need to change our understanding of health and fitness. Many of our beliefs about health and nutrition are based on marketing from the food industry. It has very little to do with actual health and fitness. The food industry takes advantage of the fact that the general public doesn’t understand that exercise doesn’t lead to weight loss.
What about carbohydrate loading for exercise?
The idea that carbohydrate loading is necessary for exercise is another industry idea.
The body has a limited capacity to store carbohydrates. Industry promotes that these are essential for intense exercise.
For non-elite athletes this is simply not true. The work of Volek and colleagues suggest otherwise. Chronic adaptation to a high-fat low-carbohydrate diet induces very high rates of fat oxidation rates (up to 1.5 g/min) .
That is plenty of fuel for most athletes to perform well. There is no need to add carbohydrates. Fat, including ketone bodies, appears to be the ideal fuel for the health benefits of exercise.
Don’t want to be a fat runner? You can lose weight while running.
If you enjoy running, you can still lose weight. The first step is to realize that it isn’t the actual exercise that will help you.
Changing your diet is necessary to get leaner. Training your body to use fat for fuel is the next step. Disrupting the idea that carbohydrates are necessary for performance is essential.
If you’re trying to lose weight, reduce your carbohydrate intake. Don’t compensate for your diet because you exercised. You can’t outrun sugar.
Further Reading:
Predictors of fat mass changes in response to aerobic exercise training in women.
Resistance to exercise-induced weight loss: compensatory behavioral adaptations.
Low-carbohydrate diets for athletes: what evidence?