The Complexity of Obesity
Obesity is a chronic global health problem affecting more than 800 million people worldwide, and it’s estimated that about 42% of Americans are obese. There are enormous health and financial consequences related to this illness. The medical costs of obesity in the US alone are estimated at $173 million annually and are expected to reach $1 trillion worldwide by 2025. The health consequences of obesity are wide-ranging and include cardiovascular disease, stroke, type 2 diabetes and certain types of cancer—all of which are among the leading causes of preventable, premature death.
Body Mass Index (BMI) is the most widely used method for measuring and qualifying obesity. It is a simple calculation of weight in kilograms divided by height—measured in meters squared. Luckily, many tools are available online to convert to English units of pounds and inches so individuals can quickly determine their status. Considering Americans’ focus on body image, it is likely that most can cite their height and weight within 3%, so BMI appears to be a great general indicator.
BMI measurements of 18.5-24.9 are considered healthy, while a BMI of 25.0-29.9 is defined as overweight, and over 30 is considered obese. While BMI may be used as a screening tool, it does not consider an individual’s body fat percentage or overall health. So, in clinical studies, it is essential to evaluate the overall health of the research subject to appreciate the clinical effects of treatments in people with conditions also related to their obesity.
Why We Gain Weight
There’s is general agreement that obesity is caused by overeating and moving too little. If you consume high amounts of energy (calories), but don’t burn off the energy through physical activity, the body will store much of the surplus as fat. If you consistently burn all the calories you consume daily, you’ll maintain your weight. Whereas you’ll gain weight if you consume more energy (calories) than you expend.
Studies have shown that cultural and genetic factors may contribute up to 70% of interindividual differences in BMI. It’s also important to understand that obesity is both chronic and subject to relapse. More than 90% of people with obesity cannot keep weight off long term. With that in mind, it is important that clinical trials include people from diverse cultural and genetic backgrounds, and that patients stay in the studies long enough to see both the depth and persistence of the treatment effects.
Childhood Obesity into Adulthood
Obesity in children is a rapidly emerging concern, with rates expected to increase by 60% over the next decade, reaching 250 million by 2030. Obese children and adolescents are around five times more likely to be obese in adulthood than those who were not obese. Approximately 55% of obese children go on to be obese in adolescence, around 80% of obese adolescents will still be obese in adulthood and about 70% will be obese past age 30.
However, 70% of obese adults weren’t obese in childhood or adolescence, so targeting obesity reduction by focusing on prevention or treatment in youth may not substantially reduce the overall burden of adult obesity. Longitudinal observational studies may be valuable tools to evaluate the long-term effectiveness of measures taken to reduce obesity during childhood and to understand cyclic relapse from weight loss.
Weight Management is More than Willpower
The biology of dieting is very complex and involves feedback loops between the body and the brain. A reduction in food consumption through dieting triggers profound appetite hormone responses—an increase in the hunger hormone, called ghrelin, and a decrease in hormones that help you feel full, including peptide YY (PYY), cholecystokinin (CCK), glucagon-like peptide 1 (GLP-1), amylin, insulin and leptin. These substances work together, signaling the brain to eat more. These mediators are potent signals set to defend the baseline body weight making it very difficult for people to sustain, much like nicotine compels people to continue smoking even though they know it is terrible for them.
The contributions of genetics are also complex, as more than 400 genes have been identified as contributors to being overweight or obese. In 2007, a single variation within the fat mass and obesity-associated gene (FTO) became the first to be reproducibly associated with human body mass. Some genes dubbed “thrifty genes” may be Darwinian evolutionary adaptations that were naturally selected in historical times when food availability was unpredictable—those who could store body when food was scarce lived, and those who couldn’t store fat would perish. Other genes seem to be programmed during pregnancy when a fetus is exposed to poor nutrition, ensuring the individual is prepared to survive anticipated nutrition constraints after birth. Unfortunately, in nutrition-rich conditions, these individuals will be pre-programmed to store fat more effectively, predisposing them to be overweight or obese.
Gaining a Deeper Understanding
As science and medicine unravel the causes of obesity, we see better treatment solutions in development.
We are prepared to assist with the research to help people reach and maintain healthy weights.
At IMA Clinical Research, our 13 dedicated research clinics are researching obesity and other co-morbid diseases such as cardiovascular disease, lipid dyscrasias, and diabetes, among others. We have created well-developed, sophisticated centralized patient recruitment platforms supported by a Patient Outreach Center to vigorously recruit patients into trials and promote patient engagement and retention for longitudinal research studies.
Our research clinics are in locations where we can access and recruit subjects from diverse genetic, cultural and socioeconomic backgrounds – all of which play essential roles in developing obesity and therefore should be included in research study populations. IMA is also uniquely situated to conduct decentralized research using its dedicated research clinics as hubs and its widely distributed network of 125 medical clinics in forty states as satellite locations. This array of sites gives IMA tremendous geographic breadth and community reach.
We support our sites with centralized processes for feasibility responses, budget development, contracting, start-up, IRB submissions, patient recruitment and accounting services to help accelerate timelines and reduce administrative interactions. This lets our research staff focus on the important things – the patients and the research!