The obesity epidemic is driven by a complex interplay of hormones, food addiction and modern dietary habits. The rise of ultra-processed foods (UPFs), along with a societal shift towards instant gratification and frequent snacking, has led to global obesity reaching record levels. According to the World Health Organization, over one billion people, or one in eight, were living with obesity in 2022. 

In the UK, UPFs currently account for 50-60% of daily calorie intake. These modern foods are engineered to be highly palatable and addictive, with a profound impact on metabolism. They often contain a mix of sugar, fat and salt, which activates the brain’s reward system and creates a powerful feedback loop that fosters cravings and overconsumption like addictive drugs. 

Leptin and insulin are key hormones in weight regulation. Leptin signals the brain to regulate hunger and energy expenditure. However, in individuals with obesity, leptin signalling to the brain is often disrupted by persistently high insulin levels, triggered by excessive consumption of sugar and refined carbohydrates. Additionally, overeating foods rich in pro-inflammatory omega-6 fatty acids, such as those containing vegetable oils, further worsens ‘leptin resistance’. This occurs as stored fat becomes inflamed, releasing pro-inflammatory chemicals into the bloodstream that block leptin signalling. As a result, despite having ample energy reserves, obese individuals continue to eat, leading to uncontrolled weight gain.

Obesity is also linked to a high ‘weight set-point’, which is the weight the brain perceives as ‘normal’. In people with obesity, this set-point is higher than what’s considered healthy. When they attempt to lose weight, the brain resists by slowing metabolism and increasing hunger, which is why dieting alone is short-lived and often results in long-term weight regain. 

Several factors beyond an unhealthy diet contribute to raising the weight set-point and disrupting metabolism. Stress, for example, increases cortisol levels, which stimulates appetite and raises blood sugar, leading to increased insulin production and fat storage. 

Similarly, lack of sleep, reduces melatonin production, disrupting cortisol regulation and metabolism. Repeated dieting attempts can also signal the brain to pre-emptively store more energy, further raising the weight set-point. Some individuals with obesity often require a trigger to jump-start their journey to lower their weight set-point. 

This may involve weight loss medications or interventional treatments such as a gastric balloon, gastric band, sleeve gastrectomy, or gastric bypass. However, there’s growing concern that a significant proportion of patients experience substantial weight regain following these therapies. Over a third of patients undergoing gastric bypass surgery experience significant weight regain within seven years. Additionally, more than 75% of patients regain a considerable amount of weight six years after sleeve gastrectomy, with similar outcomes reported after the removal of intragastric balloons. 

While these therapeutic strategies are often necessary, Mr R Camprodon, a specialist surgeon in weight loss, believes the most important step in restoring metabolic health, reducing cravings and achieving lasting improvements is replacing modern foods with nutritious, lower-calorie alternatives. Healthier choices reduce reliance on food for pleasure, making weight loss easier to maintain and lowering the risk of regaining weight. Ultimately, overcoming obesity is about understanding how your body responds to food. 

If you feel unsure and overwhelmed by the abundance of information available, Mr R Camprodon can offer guidance to help you make an informed decision. 

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