“More than one billion people worldwide live with obesity, a silent pandemic whose development and treatment we now know differ between men and women,” explains Dr Rosalía Rodríguez. As described in the article entitled “Why obesity is, above all, a disease of the brain”, while society is full of external factors that can lead to overweight or obesity, the human brain continues to operate according to ancestral rules that make it difficult to maintain weight loss. Therefore, research and medicine are undergoing a transformation in treatments, paving the way for new therapies that target the brain directly.
Obesity and overweight are often described as an excess of fat or a metabolic problem, but their deeper origin lies in the central nervous system – particularly in the hypothalamus, the region that acts as an “energy thermostat”. Because our distant ancestors lived in conditions of scarcity, where physical activity was essential for survival, the human brain developed highly effective mechanisms to preserve fat mass. However, this situation has completely changed in today’s society, where a sedentary lifestyle, stress and lack of sleep coexist with ultra-processed foods and high-calorie diets, creating a mismatch between biology and modern living.
As Dr Rodríguez explains, these external factors cause inflammation of the hypothalamus, altering the activity of the neurons that regulate hunger and satiety. A balanced diet and regular exercise can help control and reverse obesity, but in some cases, individuals exhibit a less effective “hypothalamic brake” and gain weight more easily. The difference between one case and another lies in the brain. “In the research carried out by our group, we have also observed that weight regulation is not the same in men and women due to hormonal differences and neuroimmune responses,” emphasises Dr Rodríguez. “This leads us to integrate this gender perspective into research in order to advance towards more precise and effective treatments.”
The key role of the brain and hypothalamus in obesity poses a major research challenge: developing therapies that act directly on these structures, with greater precision and fewer systemic effects. “This is where brain-targeted nanomedicine opens up a new horizon. In our group, we are developing nanoplatforms capable of selectively delivering drugs to the brain. These technologies represent a way to treat obesity at its cerebral origin, with more personalised and sustainable interventions,” argues the researcher.
Ultimately, Dr Rosalía Rodríguez demonstrates in her article published in The Conversation that obesity must be understood as a complex disease with roots in the brain, where human biological evolution and modern lifestyle exert a profound influence. This approach implies that solutions to combat obesity must go beyond diet and exercise, incorporating therapies and treatments specifically designed to modify the brain signals that regulate weight.
