From Dr. Emma Patterson who attended a course this week in San Francisco: Metabolic Applied Research Strategy (MARS)
According to the presenter, Dr. Lee Kaplan – Associate Professor of Medicine at Harvard Medical School, and world-renowned obesity researcher – the current obesity epidemic results from a failure of normal weight and energy regulatory mechanisms, which are largely the result of our modern “obesogenic” environment.
He described four drivers of obesity in our environment:
1. Altered food supply: this consists of more processed, high energy density foods, and is more about neuro-hormonal signaling than calories
2. Decreased physical activity: there is an effects on muscle, more than simply calories burned
3. Stress and distress: these have direct impacts on relevant areas of the brain
4. Drugs: steroids, anti-diabetes drugs, and anti-psychotic drugs are examples of modern drugs with relationships to weight
Body weight is usually very tightly regulated, and Dr. Kaplan described how a very slight imbalance in this regulation leads to weight gain. He gave two examples to illustrate this point. First, he said, the average energy intake in a year for an adult is 912,500 calories (2500 per day). Gaining one pound in a year results from an excess of 4,050 calories, or just 11 calories per day, which is approximately the calories in one potato chip, and this represents a 0.4% mismatch in energy balance.
He then gave an example of the subtlety of severe obesity in terms of energy mismatch. A consistent energy excess of 30 calories a day will generate enough calories for more than a 200 pound weight gain during adult life time, and this 30 calories per day corresponds to a 1.5% mismatch between energy intake and expenditure.
Dr. Kaplan reviewed what is known about obesity, as far as that obesity has negative effects of health and that bariatric surgery works for obesity, diabetes and other comorbidities. However, very few people with severe obesity get surgery (200,000 who have had bariatric surgery represents 1 in 400 people with obesity in the US). Therefore we know that there is a large unmet need for additional therapies.
Important questions we don’t have the answers to regarding obesity and bariatric surgery include:
1. Why exactly is surgery so effective?
2. What are the important differences between the procedures?
3. For which patients is surgery the best option?
4. Which procedure is the best for each patient?
Dr. Kaplan concluded that effective therapies of obesity will need to promote changes in the energy set point, affect the weight regulatory system at multiple levels, and blunt the environmental influences on body weight. He thinks that, “these requirements suggest that individualized approaches and combination therapies will be most effective.”
The goals of MARS are to answer the questions, develop and test new therapies, and bring them to patients. The course was sponsored by Ethicon Endo-Surgery, who also fund Dr. Kaplan’s research.