In less than a century, human diets have transformed in ways that our distant ancestors could not have imagined. Although it is doubtful that humankind had an identifiable “ancestral” diet, the transition of our diets from whole and minimally processed foods to energy abundance and highly refined foods represents a dramatic shift in eating patterns. …
How do drugs like Ozempic (semaglutide) cause weight loss? What happens when someone comes off of these drugs? In this episode, we discuss how these drugs (GLP-1 receptor agonists) target specific areas in the brain to suppress appetite and facilitate weight loss. We also discuss clinical trials data suggesting that these drugs and/or the weight loss that they facilitate may have cardioprotective effects. Lastly, we will also examine evidence regarding weight regain when coming off of these drugs and common side effects.
Highly processed foods have been shown to lead to weight gain and are thought to drive intake through several mechanisms. Recent research suggests that the effect of combining fats and carbs on appetite might be more than the sum of their individual effects. Highly processed foods, accordingly, might simulate increased intake via the ratio of macronutrients.
Growing scientific evidence suggests that highly processed foods are associated with increased risk of disease. Until recently, scientists were unable to study directly the effects of highly processed foods on humans. In this episode, we review one of the first highly controlled scientific trials demonstrating that ultra-processed foods lead to weight gain.
Some of the earliest changes in obesity are invisible – and they start in the brain. Of particular concern, many of the brain changes that accompany obesity bear striking resemblance to those that occur in brain injury. In this episode, we discuss how overeating can lead to inflammation and neuron dysfunction in specific parts of the brain that control appetite and energy regulation. We review the neuroscience of appetite regulation, energy expenditure, and body fat regulation. Topics include hypothalamic dysfunction of body fat regulation, leptin resistance, neuro-inflammation, and physical changes in the hypothalamus involving microglia (the immune cells of the brain). We also review what is known about avoiding and reversing these changes.
Is it possible to be metabolically healthy and overweight or obese? In this episode, we discuss the science of what makes fat healthy or unhealthy. We discuss how metabolic dysfunction in fat tissue can affect the rest of the body. We also review evidence pertaining to the “obesity paradox” and explore explanations for the associations of body mass index (BMI) and changes in the risk of disease complications and mortality. We discuss how metrics of central obesity can be used to obtain a better picture of an individual’s metabolic health. Lastly, we discuss the critical link between exercise capacity and future health, as well as how to begin to transform our existing fat stores into a healthier state.
In this episode, we discuss fat through the lens of performance and survival, and what happens when we push our energy systems to their limits. We also talk about how our bodies make adaptations via exercise to improve our ability to “burn” fat for fuel, and how our bodies conserve fuel during times of negative energy balance. Lastly, we preview the role of fat as an endocrine organ and the importance of its communication with the brain, as well as the critical role of exercise capacity for our future health.
This is our first episode on weight gain and weight loss. In this episode, we describe how, as an industrialized nation, our food supply and environment have changed in a way that, in many cases, is mismatched with our biology as humans. We explore how these changes can lead to disease and metabolic dysfunction. We discuss how the replacement of whole foods with processed foods, as well as the addition of caloric sweeteners to most of the food items within grocery stores across the nation has preceded a rapid rise in obesity and metabolic dysfunction. In this episode, we begin to discuss some of the pathophysiology related to the consumption of ultra-processed and hyper-palatable foods as well as concerns surrounding the consumption of fructose- and glucose- containing sugary drinks. We also discussed the timelines of weight gain and loss as they typically occur over the lifespan and vary according to season. This episode sets the stage for the next episodes, which will focus on the normal fat metabolism and how it may become dysregulated in metabolic dysfunction.