2024 has been a breakthrough year for health. For example, this summer witnessed the first FDA approval for non-prescription continuous glucose monitors (CGMs were previously restricted by prescription to people living with diabetes). Virtual technology continued its accessibility transformation of mental healthcare, with data indicating that over half of mental health visits in 2024 were conducted using remote technology platforms. And advancements in stem cell technology even made the first medical reversal of type 1 diabetes possible this year1.

Yet some of the most useful health insights we gained this past year concerned one of society's most urgent and widespread problems: metabolic and weight-related health conditions. Here are some of the most valuable scientific takeaways in this area from the past year.

When the investigators of the powerful new medicines, Wegovy and Zepbound, were initially trialing their effects for weight loss years ago, the prevailing theory was that these medicines primarily worked by increasing satiety hormones in the stomach, such as GLP-1 (Glucagon-Like Peptide-1). Fast-forward to 2024, and researchers now realize that much—for many people, even most—of the weight loss benefit comes from medicine-induced changes in brain regions that regulate food reward and satiety2. These medicines are so effective because they modify both the physical and psychological circuits involved in eating.

According to international data collected by the World Health Organization, in the mid-1970s, every age, sex, and race group in the U.S. suddenly began increasing in obesity rates. Since then, we've blamed fats, blamed willpower, and blamed carbohydrates—especially sugar. Yet the highest-quality nutrition studies—precisely tracking eating and weight changes among people living in controlled metabolic laboratories—suggest that it is the ultra-processing of the food itself rather than the macronutrient content that leads to weight gain and health problems3.

Ultra-processing of food in the U.S. began in earnest in the '70s. It makes food hyper-palatable, calorie-dense, fiber- and nutrient-sparse and causes us to eat more. This combination appears to be a metabolic disaster for adults and children alike.

This finding might be the hardest for most people to believe. Yet some of the most rigorous metabolic studies conducted in humans over the past decade4 show that our bodies regulate energy expenditure just like they do body temperature, oxygen levels, and other homeostatic processes. This means that when we engage in exercise, rather than raising our overall metabolic rate, our body compensates partly by reducing energy expenditure for other body processes. This homeostatic model of energy expenditure probably explains........

© Psychology Today