New Calls for a Soft Drink Sugar Tax

02/10/2012 08:19 BST | Updated 01/12/2012 10:12 GMT

It may sound astounding, but up till now conclusive evidence linking sugar consumption with obesity did not exist. Sure the rise in sugar intake has increase in tandem with our obesity rise over the last 30 years, but as readers of The Health Delusion will know, association does not equal causation. That is until the recent publications by the New England Journal of Medicine. Three studies published in the last week aim to send to rest the debate.

The first found that a genetic predisposition exists in which certain people are more susceptible to the deleterious effects of sugar in causing weight gain, and a higher intake of sugar unsurprisingly increased one's fat accumulation [1]. Looking at three cohort studies comprising of over 11,000 adults it was found that for every ten relevant genes you have your risk of becoming obese increases over three fold when you consume one or more servings of a sugar sweetened beverage daily. Don't consume the soft drinks and this genetic risk does not kick in.

The second was a randomised controlled trial of 224 overweight and obese adolescents which found that switching sugar sweetened beverages with non calorific sweetened drinks reduced overall energy intake and lowered BMI over a one year period [2]. It was important to note that when the intervention stopped the difference in BMI was no longer noticeable meaning that you can't just go on a health buzz for a short period and expect long lasting gains, these are habitual long term changes needed or else you are wasting your time.

The third a randomised controlled trial in healthy normal-weight children showing once again that replacement of sugar sweetened beverages with a sugar free alternative significantly reduces weight gain and fat accumulation [3].

With 15% of caloric intake coming from sugar sweetened beverages in obese adolescents it seems the writing is on the wall for these tasty but destructive thirst quenchers.

Sure the beverage industry will give the same old argument that obesity is a multi-factorial problem and to reduce it to the deleterious effects of sugar is a reductionist view. And, yes it could be argued that if the activity levels of youths increased, not only would they burn more calories but they would have a greater capacity to utilise their sugar intake. But, the fact is on a practical level energy expenditure is low, and to limit this adverse effect it seems the best thing we can do is slash our sugar consumption. This is especially true for the prevalent consumption of the sugar sweetened beverages which boast a high caloric content, and low satiety and compensatory dietary response. And, with these rapidly absorbed carbohydrates comes insulin resistance, beta-cell dysfunction, inflammation, visceral adiposity, and other metabolic disorders.

With the publication of these studies comes the revoicing of demands for policy implementation to limit consumption of sugar-sweetened beverages, especially those served at low cost and in excessive portions. I have previously discussed how a "junk food" tax is an idealistic, ill conceived notion, and its feasibility and outcome far different in reality than it is on paper. That is, except for soft drinks which I proposed should be taxed as high as 100%. With the findings of these latest studies, it's time to reiterate this appeal and call on policy makers to take serious action to reduce consumption of these sugar engorged liquids. We have New York City banning the sale of super sized sodas by March 2013, but really is it any more than an unenthusiastic gesture?

Seriously, at this stage who is surprised at the revelation that soft drinks are awful for our health, contributing to the obesity epidemic as well as being a major cause of metabolic syndrome. What purpose do they even serve? They are not even a qualified food group, having no nutritional value. Why are we not quashing them once and for all? What are the consequences of taking soft drinks to the extent of making them unaffordable for the majority, lower revenues for the conglomerates and greater health for the nation? It's time to stop and ask, what exactly is stopping us?

1. Qi, Q., et al., Sugar-Sweetened Beverages and Genetic Risk of Obesity. N Engl J Med, 2012.

2. Ebbeling, C.B., et al., A Randomized Trial of Sugar-Sweetened Beverages and Adolescent Body Weight. N Engl J Med, 2012.

3. de Ruyter, J.C., et al., A Trial of Sugar-free or Sugar-Sweetened Beverages and Body Weight in Children. N Engl J Med, 2012.