Dr. Philip McMillan, John McMillan

Sarah, a 42-year-old hospital administrator, had always prided herself on maintaining an active lifestyle. Despite her best efforts—regular gym sessions and a seemingly balanced diet—she found herself gaining weight steadily over the past few years. Frustrated and concerned, she enrolled in a weight-loss program and even sought psychological counseling, yet the pounds kept piling on. Nothing seemed to work, and in frustration, Sarah slacked off her exercise routine and stopped paying attention to her diet, gaining even more weight. Sarah’s story echoes the experiences of millions worldwide grappling with unexplained weight gain and its potential health consequences.

Obesity and COVID-19: New Insights

Recent research has shed new light on obesity, particularly in the context of the COVID-19 pandemic and its long-term health implications. While the severe lung disease associated with COVID-19 may be less prevalent due to widespread exposure and vaccination, concerns remain about other potential complications related to obesity.

A meta-analysis published in June 2023, which included 199 studies from the US and Europe, revealed that patients with obesity facing moderate to severe COVID-19 had a 20 to 50% higher risk of mortality compared to those with normal weight. The study also found that higher obesity was associated with an increasing relative risk of COVID-19 mortality.

One key factor in this relationship is the presence of free or serum ACE2 (Angiotensin-Converting Enzyme 2) in the bloodstream. In healthy individuals, ACE2 is typically attached to endothelial cells (a type of cell that lines the interior surface of blood and lymphatic vessels). However, in older people and those with obesity or hypertension, an enzyme called ADAM17 clips some of these attached ACE2 molecules, allowing them to float freely in the bloodstream.

A large-scale study involving 10,000 people worldwide found that obesity was more strongly associated with elevated serum ACE2 levels than diabetes, age, blood pressure, or smoking. This finding is particularly significant as serum ACE2 levels have been identified as the highest predictor of cardiometabolic death, surpassing traditional risk factors like smoking, diabetes, weight, blood pressure, and cholesterol. Cardiometabolic death refers to mortality caused by cardiovascular and metabolic diseases, such as deaths from heart disease, stroke, and other related metabolic conditions.

Understanding Obesity: More Than Just Calories

Obesity is often misunderstood as simply a result of overeating or lack of exercise. However, recent research suggests that it’s more complex than that. Obesity is frequently a symptom of insulin resistance, rather than its cause. Insulin resistance occurs when cells in the body become less responsive to insulin, a hormone that regulates blood sugar levels. Normally, when we eat carbohydrates, they’re broken down into glucose. Insulin then helps move this glucose from the bloodstream into cells, particularly muscle cells, where it’s stored as glycogen for future energy use.

In people with insulin resistance, this process becomes impaired. The body produces insulin, but the cells don’t respond to it effectively. As a result, glucose can’t be stored properly in muscle cells as glycogen. Instead, the excess glucose in the bloodstream is converted to fat and stored in fat cells.

This mechanism explains why some individuals gain weight even when they’re not overeating. Their bodies are essentially redirecting energy from muscle storage to fat storage due to insulin resistance. It also explains why simply reducing calorie intake or increasing exercise may not be enough for some people to lose weight effectively.

The role of amylin, a hormone that acts as a counterbalance to insulin, is often overlooked in discussions about weight gain. In cases of insulin resistance, amylin may be overactive, blocking the production of glycogen and leading to increased fat storage. This mechanism explains why some individuals, like Sarah, struggle to lose weight despite diet and exercise efforts.

Addressing Obesity: A Comprehensive Approach

Given the potential long-term risks associated with obesity, especially in the context of ongoing viral circulation, it is crucial to address this issue proactively. Strategies should focus not only on dietary changes but also on managing insulin resistance to effectively reduce weight and associated health risks.

As research continues to uncover the complex relationships between obesity, metabolic health, and disease susceptibility, it becomes increasingly clear that a comprehensive approach to weight management is essential. This approach should incorporate an understanding of individual metabolic profiles, targeted interventions to improve insulin sensitivity, and lifestyle modifications that support overall health.

In conclusion, the ongoing health challenges posed by obesity extend beyond the immediate concerns raised during the COVID-19 pandemic. By recognizing obesity as a symptom of underlying metabolic dysfunction and addressing it through science-based strategies, we can work towards improving public health outcomes and reducing the risk of future complications. For individuals like Sarah, understanding these mechanisms can provide new hope and direction in their journey towards better health.

This article is based on information from the video, ‘The COVID Obesity Connection: Science & Solutions‘, broadcast on 3, July 2024 on the Vejon Health YouTube channel. Watch the original video.