Losing weight without eating less calories

In the previous blogposting, I argued in favor of a whole food diet. Such a diet allows us to lose weight without eating less calories. The argument was based on invoking the extreme robustness of living organisms. Evolution should not have made us prone to becoming overweight when we eat as much as we please! Animals in the wild don’t get obese, so why are we prone to getting overweight?

Could it be that most animals in the wild are just at the limit of being in calorie deficit? This is the traditional explanation, but it’s not all that plausible given the robustness of living organisms in their natural environment. If our ancestors in the wild were teetering at the edge of starvation, we wouldn’t be here. Nevertheless, this is a popular view and it misinforms us about the way we should tackle the obesity problem.

Animals in the wild are generally not teetering at the edge of starvation, they are thriving. Their bodies simply adjust the metabolic rate to balance their energy budget. They maintain a healthy setpoint for their fat reserves.

The reason why we’re prone to becoming overweight is because the food we eat is not natural. Our food contains an unnaturally high amount of refined fats and sugars. The key to long term sustainable weight loss is then to eat whole foods. But why would this make a difference given that most of us do get the recommended amounts of vitamins and minerals?

As I pointed out here, getting all our calories from whole foods will yield far more fiber and magnesium, about double the RDA. So, boosting the fiber content of the diet by eating more whole foods is an obvious way to improve the diet. In this blogposting I’ll consider why eating more fiber will lead to weight loss. I’ll conclude with my recommendations for getting started with losing weight according to the methods I advocate.

Eating more fiber lowers the bodyweight

As I explained here in the previous blogpost, the amount of fat reserves we have is regulated with the aim of keeping our energy reserves stable. This is implemented by hormones excreted by fat cells. If fat cells become emptier, the metabolic rate will be slowed down. Fat cells will then start to accumulate more fat as a result. Traditional dieting methods don’t work well, as they fight this mechanism.

The smart way of losing weight is therefore to lower the setpoint for body fat. Once the setpoint is lowered to the target body weight, you can eat pretty much as much as you like, and you’ll not gain much weight. If you do gain a bit of weight, e.g. after Christmas, you’ll be back to your ideal weight within a matter of days, without having to diet.

So, is it then plausible that getting more fiber in the diet will lower the body fat setpoint? Why would fiber have such an effect? It’s perhaps better to ask why not getting the naturally normal amount of fiber will have the opposite effect.

Why does eating more fiber lower the body weigh?

A diet low in fiber in the natural context means that we’re not eating a normal amount of plant-based foods. We would instead be surviving on animal food products. Such a situation could be typical for a harsh winter, or a drought and it comes with a high risk of famine. Clearly, this would have led to a body design via natural selection that would increase the body fat setpoint when eating a low fiber diet, if such a body design were physiologically possible.

So, is it possible for the body to increase the body fat setpoint if we change the amount of fiber in the diet? If we change the amount of fiber in the diet, does the body get a signal that it can act on to modulate the metabolic rate?

How fiber is able to change the body fat setpoint

What is known is that the fiber we eat is food for our intestinal microbes. The more fiber we eat the more intestinal microbes we have and we’ll also have a more diverse set of such microbes. These microbes produce chemical compounds, some of which such as butyrate play a role in many biochemical processes in the body.

The net effect of these chemical compounds is still the subject of scientific investigations. But the mere existence of all these chemical compounds that are capable of influencing metabolism, makes it possible for fiber to modulate the metabolic rate. We can then assume that as a result of evolution we would have ended up with a body fat setpoint that depends on fiber intake.

Other ways to influence bodyweight

Besides eating more fiber, we can think of other ways to get to a lower body fat setpoint. Let’s first look at sleep. It is known that sleep deprivation tends to lead to weight gain, biochemical pathways by which this happens in case of accute sleep loss have recently been uncovered. But it’s helpful to try to understand why evolution would have led to this outcome.

Why sleeping less causes weight gain

Why would animals in nature sleep less? Typically this will happen if they need more time to find food. This is then a signal that points to an increased risk of food shortages. One should thus expect that sleep deprivation will cause to the setpoint for body fat to increase.


The effect of exercise on bodyweight is usually assessed via the amount of energy burned in exercise sessions. One then reaches the conclusion that exercise isn’t all that effective compared to an energy restrictive diet. It takes a massive amount of exercise to burn off the energy consumed in one big meal. However, as I’ve pointed out in this and the previous blogpostings, what matters more for the bodyweight on the long term is the setpoint the body chooses to maintain.

Why would the setpoint for body fat change due to exercising regularly? When living in nature, being physically fit means that you are able to walk larger distances to find your food should that be necessary. This thus lowers the chance of experiencing food shortages. But it’s no good if far away you can find a lot of food, if it takes more energy to get there than is present in the food. But the lower the body weight the less energy it costs to walk long distances.

The fitter you are, the lower your body fat setpoint

So, the fitter we are the more advantageous it is to have a lower bodyweight to prevent food shortages. We should thus expect that evolution has led to a body design that lowers our setpoint of body fat if we become fitter. Exercise is thus a good way to maintain a healthy bodyweight. Even short bouts of exercise that don’t burn a significant amount of calories can be helpful. What matters is then that physical fitness is maintained, rather than any individual exercise session.

Intensive exercise sessions that do burn lots of calories are, however, going to be more effective. If you burn 1000 Kcal by running for an hour then that will give you a lot of room to eat a lot more. It also enhances the appetite you need to eat healthy foods.

Eat at least 80 grams of fiber a day

As I pointed out here, eating 2500 grams of whole foods typically yields 70 grams of fiber. But we don’t eat only energy rich foods, we also need to eat vegetables and fruits and these foods also contain lots of fiber. A good diet based on whole foods should then yield at least 80 grams of fiber.

The problem is then that eating this way requires gradually getting used to the large amount of fiber. Also the volume of the food will be much larger than people are used to eating. Indigenous populations who eat this way who come into contact with Western civilization very quickly start to eat the Western-style low fiber high fat diet and then start to experience high levels of obesity and type-2 diabetes.

Once accustomed to the Western diet there is no easy way back to the original diet. Just like our muscles, the gut also degenerates when you don’t use it. Not eating enough fiber means that you lose the gut flora and it takes lots of time and effort to regain it. It this makes sense to think of this issue as a “gut fitness” issue. I’ll discuss this in the next blogposting. I’ll also talk about other health aspects of a whole food diet besides obesity.

Getting started on losing weight without eating less calories

If you want to lose weight by eating more fiber, I can recommend starting slowly by getting used to a low fat, high carb diet. This diet program (paid link) is an excellent way to start. You’ll then gradually eat more fiber while you’ll start to lose weight. It’s also helpful to learn to prepare tasty healthy meals. I can recommend this book (paid link) on vegan recipes. Even though I’m not advocating veganism, it’s still healthy to eat vegan menus, and one can always add some meat to a vegan plant-based meal.

A more rigorous way to get started is to follow the Forks over Knives diet (paid link) . This is again a vegan diet but a low fat one,it will you bring close to what I’m arguing for here. My arguments presented in this blog are not always in agreement with these vegan programs or the arguments presented in the high carb weight loss program, but what matters is that the conclusion on what type of a diet is the best to eat, is quite similar.

Another possibility is to lose weight under my personal guidance. You then need to fill in this form.

Leave a Reply

Your email address will not be published.