A big debate currently exists regarding what contributes more to one’s loss of weight. If you had to opine which has a greater effect on your weight and weight loss programme, which would you choose: Exercise, or reducing sugary food consumption? We know they both contribute, but which do you think contributes more?

The debate has been centred around the new marketing policy reportedly adopted by Coca-Cola, the world’s largest producer of sugary beverages. The company is reported to be funding influential scientists and ‘

so-called’ health-promoting organisations to proclaim, through medical journals, at conferences, and through the media, that people are currently more fixated on what they eat, whilst more benefit supposedly would be obtained through exercise.

One exercise scientist from the controversial new organisation, Global Energy Balance Network, says that most of the focus in the popular media and in the scientific press is on “eating too much” and blaming fast food and sugary drinks, yet he claims there is no compelling evidence that such is the cause.

The misleading message

Other health experts, however, say such a message is misleading, as it deflects the criticism from the role that sugary drinks have played in the spread of obesity and Type 2 diabetes. So, they think that Coca-Cola, which has provided funding for this new organisation, is using them to convince the public that physical activity is enough to offset a bad diet, despite evidence existing that exercise has only a minimal effect on weight when compared with what people consume.

This clash over the science of obesity comes during the period of rising efforts in the United States of America (USA) to tax sugary drinks, remove them from schools, and stop companies from marketing them to children. As a result of such valiant efforts, consumption of full-calorie sodas by the average American has been reduced by 25 per cent.

As sales by Coca-Cola and similar companies have been slipping, accompanied by a huge political and public backlash in the USA against sodas, and major cities trying to curb such consumption, strategic efforts have been taken by these companies. Last year, US$1.5 million was donated to the new non-profit Global Energy Balance Network, purportedly to support scientific research related to beverages and topics such as energy balance.

Partnering with soda and fast-food companies

Further, Coca-Cola has been partnering with some of the foremost experts in the field of nutrition and physical activity. Likewise, the American Society for Nutrition as well as the Academy of Nutrition and Dietetics have been criticised by public health advocates for forming partnerships with companies such as McDonald’s, Kraft Foods,

Pepsi Company, and Hershey’s. Dietitians have also faced criticisms for taking payments from Coca-Cola to present that company’s soda as a healthy snack. The erroneous message is that obesity is not about the foods or beverages you are consuming, but that you are not balancing these foods with exercise.

However, an even greater concern now is that companies like Coca-Cola are going a step further by recruiting reputable scientists to make the case for them. Critics state that such an approach was reminiscent of tactics used by the tobacco industry, which enlisted experts to become ‘merchants of doubt’ about the health hazards of smoking. The end result is to get researchers to confuse the science and deflect attention from dietary intake.

What the research shows

Physical activity is important and certainly helps, but exercise burns far fewer calories than most people think. A 12-ounce can of Coca-Cola, for example, contains 140 calories or roughly 10 teaspoons of sugar. You would, therefore, have to walk three miles to offset that one bottle of Coca-Cola. In one of the most rigorous studies of physical activity and weight loss published in the journal Obesity, scientists recruited 200 overweight, sedentary adults and put them on an aggressive exercise programme. Their diets were kept constant and they were not allowed to make any changes.

The research participants were monitored to ensure they exercised five to six hours each week, which is more than double the 2.5 hours per week that is recommended by US Federal Guidelines. After one year, the men had only lost an average of just 3.5 pounds, while the women lost only 2.5 pounds. Almost everyone was, therefore, still overweight or obese. So, whilst adding exercise to a diet programme does help, if you wish for significant weight loss, you must greatly reduce the sugary content of your daily diet.

The way forward

The strategy, therefore, has to be a combination of the two approaches – eat and drink less, and exercise more. Weight loss involves a combination of complex factors, but energy balance is an important concept since, for most people, weight gain is about calories in versus calories out. So whilst people can lose weight through several means, many research studies suggest that those who keep it off permanently consume fewer calories. Further, growing evidence also suggests that maintaining weight loss is easier when people limit their intake of high-glycemic foods, such as sugary drinks and other refined carbohydrates that sharply raise blood sugar. What therefore will be your approach?

Derrick Aarons MD, PhD is a consultant bioethicist/family physician, a specialist in ethical issues in medicine, the life sciences and research, and is the ethicist at the Caribbean Public Health Agency (CARPHA). (The views expressed here are not written on behalf of CARPHA)