Who’s To Blame? Alternative Approach Against Problem of Obesity
Date: Thursday, November 16th, 2000
Title: “Attacking the Obesity Epidemic from a New Perspective: Can Policy Be Used for Prevention?”
Speaker: Dr. Kelly Brownell, Yale University, New Haven, C.T.
Dr. Brownell described, and gave support for, his hypothesis that responsibility for the current obesity pandemic rests primarily with environmental factors influencing our society. The rising obesity pandemic threatens to increase dramatically the prevalence of diabetes and to curb the gains made in reducing coronary heart disease. An environmental, ‘public health’ paradigm has advantages over the current ‘individualistic’ models for developing prevention strategies.
Medicine and society have long sought a target upon which to assign blame for obesity, and the targets fall into three general categories: the individual, biology, and the environment. Focus on individual and biological causes for obesity have far out-weighed any attention on environmental ones. The biological influences include genes, age and gender. Behavioral influences come from the combined effects of past habits, cognitions, beliefs and attitudes. Environmental influences can be divided into macro (e.g. national) and micro (e.g. school) environments; each with physical, economic and socio-cultural components. The impact of any energy imbalance (positive or negative) on fat mass (i.e. body weight) may be opposed by changes in physiological moderators (e.g. nutrient oxidation, metabolic rate, spontaneous activity). Biological factors moderate the impact of energy imbalances in the environment, but the cause and remediation of such an imbalance rests with the environment. For example, famine-induced drops in fertility within societies during war time are caused by the environment, but there will still be large variability in fertility within that population because of biological moderators.
This model is used in many public health problems, and has proved valuable in public health efforts to reduce infectious diseases, road crashes, and smoking. The environment is the same in both models and is clearly the most fruitful area for the prevention of obesity. Environmental factors that contribute to obesity have been largely overlooked. Such factors include the types and quantities of foods available to the population, and the cultural messages experienced by societies that might allow obesity to manifest more easily in one culture than in another.
The environment in most industrialized and developing nations has become nutritionally toxic. For example, the most accessible food sources in our nation today are so called ‘junk-foods’, i.e. foods of poor nutrient value. These foods are scientifically tailored to be extremely palatable, so that the populace will consume them in abnormally large quantities. There is a strong economic incentive for such a seemingly ridiculous exploit: If the food industry can develop a mass-produced, inexpensive product that will have broad appeal and be chosen over any competing item, why wouldn’t they do so? The economic incentive must be very strong, since ‘fast-food’ chains are among the first industries to arrive in countries with fast growing populations and economies, such as China and the countries of the former Soviet Union. These foods are packaged to the public with extravagant advertising campaigns, and currently there are no public health initiatives to deter this industrial exploitation.
In addition to the foods themselves being toxic, our physical environment has grown toxic too. Most societies have become increasingly inactive, with increased dependence vehicular transport and passive leisure activities, such as watching television. In addition, many public schools have cut their physical education programs so that they can afford the expense of training their students to use computers and related technologies.
The food industry has been particularly active in recruiting new customers (i.e. children) at public schools, by paying large sums for exclusive cafeteria contracts, so that they can sell their products in school cafeterias to the exclusion of healthier alternatives. The soft-drink industry has also exploited public schools to sell their products to children. They will offer lucrative financial rewards in exchange for exclusive contracts with a school district. The result is that the school district depends on these companies to subsidize more costly programs, while children develop poor nutritional habits, such as consuming caffeinated, high-sucrose solutions, simply because they are so accessible. School officials are even asked to place vending machines in convenient areas throughout the school so students can have access to them all day.
What can we do to reverse this trend? Dr. Brownell offered incentives and deterrents to the problem. In addition to finding ways to make physical activity as easy and convenient as access to food of poor nutritional value, we ought to regulate advertising aimed at children so that they aren’t bombarded with images linking unhealthy foods with free toys. Secondly, we need to ban public schools from contracting with the food industry and eliminate access to such foods at schools altogether. If we make healthier foods readily available to children throughout the day throughout their individual development, they are much more likely to maintain healthy eating habits for the rest of their lives. This is precisely why the food industry has aimed its advertising and accessibility efforts at children. To meet this goal, we might need to subsidize healthier alternatives, since they cost more to produce, maintain and distribute. This effort will still be cheaper than having to staff more school nurses to treat the increasing numbers of school-age children with diabetes. Finally, taxes could be levied on the sale of foods that have poor nutritional quality. This option is the least appealing because it doesn’t offer any alternative to the problem, but it may at least serve as a minor deterrent and help finance the aforementioned subsidized programs. All of these efforts will work to shift the profit margin that is now earned by the food industry, and could be an incentive to develop inexpensive, convenient, and palatable foods instead of those currently used.
Q. Genetic variables impact both the prevalence of the problem and the population afflicted, so how can you really separate out which variables are contributing most to this epidemic?
A. Basically, the varied genetics in the same environment explains the prevalence, so regardless of the population’s genetic make-up, the prevalence can be improved by improving the environment.
Q. Increased energy consumption in a population increases both reproduction and obesity rates; but eventually, could potential fertility problems arise in association with complications from such high rates of obesity?
A. There is not very much work on this issue in humans- certainly not from an epidemiological perspective.
Q. If the environment changes but the population does not, won’t the distribution in body weights still be the same?
A. Probably, but the aim is to shift the mean weight of the population into a healthier range, not to change the distribution per se.
Q. Has the distribution of obesity in the U.S. changed across all socio-economic (SES) groups, or is it mostly at certain extremes?
A. The change in the prevalence of obesity has occurred across all SES groups and is not limited to certain segments of the population.
Q. Has the increase in obesity altered life expectancies in the population?
A. This question is impossible to answer right now because it is confounded by the rapid advances in medical treatments, but one could infer that since obesity leads to diabetes and heart disease, and both of these illnesses are associated with lower life expectancy, life expectancy in general may be less than optimal.
Q. Are there any safety concerns regarding caffeine consumption in children?
A. Well, at present there are controversial concerns about caffeine in adults, so until it is clear that the product is safe, encouraging its consumption in children seems a bit careless at best.
Q. But isn’t soda a relatively low-calorie food? Why is there such a concern regarding soft-drink consumption- is there evidence that this leads to weight-gain, or increased energy intake?
A. Urging children to drink sugar solutions is not an effective way to help them lose, or maintain, their weight. No matter how one considers this, drinking a caloric beverage will add to the net energy consumed in the day.
Q. The public health evidence linking obesity-prone nutrition to morbidity and mortality is just not as direct as that which has linked tobacco to lung cancer. How can we advocate such a strong public policy stand when, as scientists, we do not have explicit evidence directly linking foods of poor nutritional value to illness?
A. As Charles Dickens once said, “it was the age of wisdom, it was the age of foolishness”. In other words, it might not always be prudent to use the cautious, scientific method when it comes to instituting public health policies for our society. After all, this may be partly what took us so long to acknowledge the harmful effects of smoking.