Why is stress making you gain fat?

Losing weight is not just a matter of calories. Many health and lifestyle factors have to be taken into consideration when aiming for fat loss. Why? Because they create metabolic and hormonal mechanisms that have a direct impact on the calories we consume, the place where we store fat and what we burn to create energy: sugar, fat or muscle.

The major factor is stress management. Actually, stress is the most significant issue we have to deal with nowadays and it is important to understand how it affects our health, silhouette and well being and how to deal with it on a daily basis. You may have already noticed that your diet and training routine are not always enough, they can even worsen the situation if not adapted.

Stress is a survival reaction

Initially, stress is not as bad as we think, indeed it is a survival reaction. Human beings are made do deal with intense stress situations such as facing predators, famine, natural catastrophes, finding food, etc. Those are unpleasant, yet temporary, stressful situations to which we need to respond quickly.

When we are in danger, the brain sends signals to the adrenal glands which send hormonal signals in the body (adrenaline, noradrenaline, cortisol). The role of those hormones is to increase the levels of sugar and fat in the blood so that it can be then transformed into energy and thus enable us to react (run, fight, etc.). We also use amino acids from the muscles and glycerol from the fat stores.

Once we have all this energy available we can react and move. Then, we secrete other hormones: testosterone and growth hormone. Their goal is to repair the tissues, rebuild muscle and encourage the use of fat so that the body stays lean, fast and strong and capable of facing another threat. Then the adrenals send a message to the brain to indicate that the body can go back to a rest and recovery state.

So what’s the problem?

The problem is that nowadays, our stress is completely different. Our lives are more sedentary, we don’t have to run away or fight predators but we would rather have to face financial difficulties, stressful jobs, traffic when going home and others. The answer to those situations doesn’t imply an intense physical activity but our brain doesn’t make the difference and initiates the same hormonal response.

So our bodies still secretes all those hormones in large quantities and the sugar and fat levels in the blood increase but, as we don’t move, we don’t use it to produce energy and we don’t produce the hormones that are suppose to help us stay lean. Moreover, this stress is not temporary but most of the time chronic and it forces the body to work even more each time and this will particularly increase the cortisol secretions.

Cortisol has a major impact. It lowers meals frequency but increases meals size and hunger on the long term as well as the need to eat fat and sugar. It all comes down to our survival instinct: if you need to survive to famine and hide from predators you have to eat less often but more nutrient dense food. And at the same time, you must save as much energy as possible so you might enter a “hibernation” mode which is to say that you will have a lack of motivation and even feel depressed because your brain will want you to move as little as possible.

So less movement, more sugar and fat consumed, bigger portions, more fat storage, I think you get the point.

Cortisol also tells your body to store more fat around the abdominal area than in the rest of the body because energy is created in the liver and, in case of emergency, you need to have a quick access to fat stores. That’s the reason why cortisol is also called the “abdominal fat hormone”. [1]

When cortisol and insulin are combined

But things are not that simple and cortisol’s action is not the only factor. Indeed, hormones must never be considered alone, it is the interaction between them that counts most. Not every overweight or obese person has high levels of cortisol. But it is for sure an aggravating factor which is combined with high levels of insulin. Let me explain why.

Insulin secretion is also a protective process. When there is too much sugar in the blood, which is dangerous, insulin tells the fat cells to keep their fat so that the body only uses sugar to create energy, enabling the blood sugar levels to decrease quickly. So insulin blocks fat burning.

And as we already explained, in stress situations, cortisol will tell the body to increase the blood sugar level in order to be able to react. So cortisol and insulin have an opposite action and they will work even more in order to counteract one another. It will then come to a point where they are both so high that no other hormone will be able to counteract them (not even the testosterone or growth hormone that are supposed to keep the body lean). Insuline will tell the body to store fat, then cortisol will tell the body to store this fat mainly around the abdominal area (but not only) and to use the muscle instead to create energy.

More (belly) fat, less muscle, and this is even worse for people who have a high carbohydrate diet as it increases insulin secretions.

Your lifestyle also counts

As we explained, the most important factor isn’t the level of a single hormone but the ratio between different hormones which are supposed to compensate one another and create a hormonal balance.

Growth hormone and testosterone are antagonist hormones which are supposed to counteract the action of cortisol and insulin. Their secretions are increased through proper sleep, intense training and sufficient protein consumption.

People who suffer from sleeping disorders, who are engaged in what we call chronic cardio (perfoming too much medium intensity cardio training like running) and people who don’t eat enough animal protein are at higher risks of suffering from the effects of stress on their body composition, and health obviously as the abdominal fat increases the risk of cardiovascular diseases. [2][3][4]

So what’s the solution?

The first and most important step is to understand how your body works and why you can struggle with weight loss even when you eat less and train more. Then, you can address the issue in many ways.

1) Sleep

We will never repeat this enough. Sleep early and at least 7 hours each night. Turn your screens off two hours before sleeping, stop drinking coffee at 2 pm. You’ll find more advise on how to improve your sleep in our article Improve your sleep in 9 steps.

2) Intense training.

It is better to practice short and intense training, whether it is cardio (HIIT, Tabata, sprints) or strength training with heavy weights. Medium intensity, long duration cardio training should be avoided.

It is important to be aware that an unadapted training routine can be a source of stress and worsen the situation. It is not about training more but training smart.

3) Low intensity training

On the other side, very low intensity activities such as leisure low paced walk or stretching help decreasing the effect of stress. A 30 minutes daily leisure walk, in nature if possible, is a great way to lower cortisol.

4) Eat more protein and fat and less carbs

Eating enough protein and fat and lowering your carbs intake will enable you to maintain your muscle mass and feel satiated without increasing insulin.

5) Have breakfast and eat more often

Cortisol is higher in the morning and it gets higher as you keep fasting, so if you are not used to having breakfast you might want to change this habit and go for proteins and fat instead of carbs for breakfast. You might also try to eat more often, or add morning and afternoon snacks to your diet.

Intermittent fasting, though it is known for helping people losing fat, is not adapted to everyone, and you should be very careful if you are exposed to stress and all the more if you are a woman.

6) Eat raw cocoa

Cocoa is rich in PEA (phenylethylamine) which action imitates dopamine and reduces cravings and the need to eat fat and sugar.

7) Adaptogens

Adaptogens are plants and herbs that are proved to help decreasing stress levels and balancing your hormonal, nervous and immune systems. Supplements such as Rhodiola or Ashwaganda are a good choice.

8) Change your lifestyle

Last but not least, but for sure the most difficult one. If your lifestyle is stressful, you may consider making big changes in your life (the place you live, your job, etc.) Those are more long term decisions but sometimes we need to find the courage to point out the real issues.


[1] Dr. Pecoraro, UCL, San Francisco, Progress in Neurobiology (2006, volume 79).

[2] American Journal of Physiology, Endocrinology and Metabolism (august 2008)

[3] October 1997 issue of Human Reproduction

[4] 2000 issue of the Journal of Clinical Endocrinology and Metabolism (Volume 85 # 2)

Image credit : Thornypup

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