You embarked on the ketogenic diet journey and now you aren’t hungry.
Eating fewer calories in an effort to lose weight and improve body composition typically conjures up the idea of feeling hungry while counting calories.
After all, doesn’t calorie restriction make you hungry? For the average dieter, this is the case.
If you’re used to eating 3,000 calories a day and suddenly restricted yourself to 1,500, you can imagine how hungry you’d feel (and you’d probably be right to some extent).
But not all diets are the same, nor are their effects on hunger. The ketogenic diet has the opposite effect on dieters.
That’s fantastic, right?
But where did your appetite go? You’re not hungry on keto, why?
Let’s find out!
The Role of the Brain
The ketogenic diet affects appetite and much of it comes down to the role that the brain plays in regulating hunger.
When your body requires more food, it’s the brain that communicates this fact. This may sound simple enough, but the process doesn’t always work optimally in every person.
Some people who continue to feed themselves despite being severely overweight may have an impairment in how the brain signals satiety.
As a result, they tend to take in far more calories than they require.
The hypothalamus of the brain manages the feeling of fullness after meals. Once we eat a certain amount of food, the hypothalamus controls the communication that we no longer need to feed ourselves (3).
But how exactly is this satiety regulated in the brain?
One theory suggests blood glucose levels have a huge impact on feelings of hunger.
As the level of sugar in the blood decreases between meals, signals are sent to receptors in the brain, after which appetite increases.
The basis behind this “glucostatic theory” is that a reduction in glucose utilization in the brain leads to hunger, while increased glucose utilization leads to a reduction in hunger (4).
In addition to the levels of glucose in the blood, other factors play a role in appetite stimulation, such as the number of calories consumed and the types of macronutrients ingested.
But the ketogenic diet looks a little different from other diets when it comes to hunger levels. While this diet is associated with the consumption of fewer calories, it’s also linked to a decrease in hunger.
Keto dieters are supposed to steer clear of carbohydrates, leaving only protein, fats, and certain vegetables to feast on.
Since carbs tend to make up the majority of the typical diet, it makes sense that a large chunk of calories are slashed when carbs aren’t depended on to fill the daily caloric total.
The ketogenic diet allows participants to eat as much as they like as long as they focus their calories on specific proportions of macronutrients.
There is no calorie counting involved.
Yet despite the fact that there is no need to count calories, participants in ketogenic diets tend to consume less food simply because their hunger is satisfied.
And with less food consumption and caloric intake comes a decrease in weight. But what is it about the ketogenic diet that has dieters feeling less hungry?
Ketones’ Role in Suppressing Hunger
But what exactly do ketones do to help suppress the appetite?
One theory could involve the stabilization of blood glucose.
In a state of ketosis, the body does not experience fluctuations in blood glucose levels, as is the case on a typical carb-filled diet.
Such flatlining of blood glucose levels could lead to better signaling of hunger (7).
Obviously, a suppressed appetite is good for keeping the number of calories consumed at bay.
The basic premise of weight loss involves consuming fewer calories than are expelled. The fewer calories you eat compared to the number you expel, the more weight you’ll lose.
However, it’s not always so simple.
Hormones and Appetite Regulation
Your appetite is controlled by how hormones and the brain interact with each other. Unfortunately, the average American diet often causes impairment in hormone function, leading to an increase in hunger (8).
On the other hand, the ketogenic diet has been linked to a reduction in hunger symptoms by having a suppressing effect on hunger hormones (9).
In particular, two hormones come into play for the regulation of appetite: leptin and ghrelin.
Leptin is released after an increase in food intake or body fat.
This hormone is able to tell the hypothalamus the current state of the body’s energy level.
Leptin basically tells the hypothalamus that the body has enough fat, which should lead to a reduction in food intake in a healthy individual (10).
Ghrelin is a hormone that’s secreted by the stomach and depends on the food being eaten. Before the body is fed, ghrelin exists in elevated levels in the body.
This is when the brain is told that the body is hungry and needs to be fed. After eating, the level of ghrelin decreases and the body is told to stop eating as no more food is required (11).
As such, both leptin and ghrelin are important regulators of appetite.
In a state of ketosis brought about by following the ketogenic diet, an increase in ghrelin is suppressed, which can reduce feelings of hunger.
In fact, studies have shown an association between ketone production on the ketogenic diet and the suppression of ghrelin, which partially explains why dieters don’t feel as hungry despite the cut in calories (12, 13).
Not Hungry on Keto, But Are There Side Effects?
Not having much of an appetite can be positive for those striving to shed unwanted body fat. But are there are drawbacks to losing your appetite while on the ketogenic diet?
Yes, there are certain negative side effects associated with long-term loss of appetite, including the following (14):
- Lack of motivation to participate in activities
- Less stamina and endurance
- Mental exhaustion
- Bowel issues
Not having much of an appetite may help you lose weight, but it could also be a deterrent in allowing your body to get the food it needs to function properly.
In the end, counting calories while on the ketogenic diet might be a good idea because going under a certain caloric amount could lead to negative effects on your health.
The Bottom Line
There are plenty of things that can sabotage weight loss efforts and hunger is perhaps the most significant. A raging appetite can lead to consuming far more calories than the body needs to create a calorie deficit and lose weight.
One of the great things about the ketogenic diet is that it can help suppress appetite despite a reduction in calories. Studies have been conducted on ketosis and appetite suppression, so there’s science to back up this claim.
Just be careful that you’re feeding your body with food in healthy proportions so that you maintain your overall state of wellbeing while on your way to weight loss.