How Obesity Affects the Brain

Obesity is associated with increased intestinal permeability and with an increased influx of toxic compounds into the brain.
How Obesity Affects the Brain
Saúl Sánchez Arias

Written and verified by the nutritionist Saúl Sánchez Arias.

Last update: 07 October, 2022

Obesity alters our body’s normal functioning. In addition to increasing the risk of developing diseases in the medium and long term, it can also affect cognitive performance. For this reason, it’s essential to lose weight if you suffer from obesity. This will help to significantly improve your quality of life. Below, we’ll show you how obesity affects the brain.

Obesity affects the brain

Obesity can reduce brain performance and accelerate brain aging. This occurs as a result of oxidation and inflammation processes. This is stated in an article published in the journal The Proceedings of the Nutrition Society. Furthermore, this condition of obesity could increase the risk of dementia in older individuals.

On the other hand, being overweight is linked to a worsening of metabolic health markers. This situation can increase the feeling of tiredness and fatigue, which not only occurs in the muscles, but can also extend to cognitive function.

As a result, obesity is a condition that can affect several of the body’s main systems and processes. Suffering from this disease prevents the body from functioning properly.

Obesity can precipitate cognitive deterioration, and, for years it has been associated with an increase in dementia processes. But, in addition, an article published in the International Journal of Molecular Sciences relates the condition of excess weight and obesity with an increased risk of developing Alzheimer’s disease.

The proposed model is an increase in the permeability of the intestinal and blood-brain barrier. From here, there’s an increase in the beta-amyloid compounds that are synthesized and enter the central nervous system. This is related to the risk of suffering from this type of neurodegenerative disease.

To reduce the impact of this situation, supplementation with probiotics can be positive. These bacteria colonize the walls of the intestinal transit and reduce the creation of toxic waste products and the permeability of the intestinal wall.

Some neurons.

Dietary guidelines to lose weight

In order to prevent obesity, it’s necessary to carry out a series of dietary strategies. The aim is to improve food quality and increase how fast you lose weight. Both intermittent fasting and carbohydrate restriction are very effective in the clinical setting.

In addition, there are a number of supplements or substances that can help the weight loss process. Consuming tea or coffee frequently and adding spice to meals are strategies that report a high level of efficacy.

Although some types of obesity are linked to certain genetic factors, in most cases the reasons are environmental. People suffering from this disease usually have unhealthy lifestyle habits, which leads to the accumulation of fat in adipose tissue.

For this reason, changes in diet and the implementation of an exercise routine usually produce satisfactory results.

An obese woman.

Obesity is a risk factor for cognitive impairment

As we have said, obesity is a disease that can affect several organs in our bodies. One of them is the brain. Being overweight can cause a reduction in cognitive performance, as well as a higher incidence of neurodegenerative pathologies.

To prevent this type of situation it’s essential to reduce body weight. This objective can be achieved by improving the individual’s eating habits and increasing the level of physical activity. From here, a number of strategies can help to achieve this goal.

Obesity needs to be tackled in order to prevent the appearance of pathologies associated with aging.

The consumption of foods with antioxidant and anti-inflammatory properties may be able to delay the development of this type of disease. Probiotic supplementation may also be able to reduce the incidence of cognitive problems.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.


  • Dye L., Bernard Boyle N., Champ C., Lawton C., The relationship between obesity and cognitive heatlh and decline. Proc Nutr Soc, 2017. 76 (4): 443-454.
  • Jones NS., Rebeck GW., The synergistic effects of APOE genotype and obesity on alzheimer’s disease risk. Int J Mol Sci, 2018.
  • Martínez, I. V., Román, J. L., Gonzálvez, A. M., & García, J. V. (2005). Obesidad y síndrome metabólico en pacientes con esquizofrenia. Revista Psiquiatría Biológica [revista en internet]12(2), 39-45.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.