ALL FOODS ARE HABIT‐FORMING – WHAT I WANT TO KNOW IS WHICH WILL KILL ME!

Abstract

Gearhardt et al. [1] are right to point out that ‘food addiction’ is much more than a metaphor, owing to the fact that the neuroendocrine mechanisms underlying the formation of dietary habits are often precisely those acted on by drugs of addiction. Just as exposure of tobacco companies' explicit efforts to increase the addictive potential of their products helped to generate public support for stricter regulation in the United States, evidence of similar actions by food producers may well serve the same purpose. It is telling, however, that the taxes and restrictions on marketing eventually placed on tobacco were applied to all tobacco products, regardless of how addictive or carcinogenic they happened to be [2]. An analogous outcome for processed foods, I would argue, is not feasible. The cost efficiencies inherent in industrial-scale food production are enormous, making it unrealistic to expect most consumers to return anytime soon to the days of fresh fruits, vegetables and meats purchased directly from the local grower. Every one of the remedies the authors mention—taxation, subsidies, restrictions on marketing, availability or trade, and even corporate responsibility—will require the development of very specific rules that differentiate ‘bad’ products (which will be subject to regulation) from ‘good’ (which presumably will not). The food industry has a long history of reformulating products in response to conditions in the market-place [3–5], and public health improvements will hinge critically on the extent to which producers are induced to deliver healthier industrial foods to the consumer. With regard to choosing the particular product characteristics that most damage public health, ‘hyperpalatability’ seems a poor candidate. There is very little evidence that hyperpalatability, considered in isolation, causes illness. It can be argued that today's highly processed mass-marketed foods have been (perhaps unintentionally) designed to induce a biological addiction event. However, the reason industry methods succeed so persistently is that they take advantage of evolved predilections that served important adaptive purposes in the pre-industrial world, and probably still do [6,7]. There is every reason to expect that people also become ‘addicted’—in both the physiological and behavioral senses of the word—to any delicious food (healthy or not), experienced in the right context. Consider again the case of tobacco. Instead of targeting the leaf itself, public health advocates could have sought to place restrictions on particular characteristics, such as nicotine or ‘tar’; but scientific uncertainty regarding the contribution of particular product characteristics to addiction or health outcomes would have provided easy fodder for defensive legal action by the industry. Moreover, singling out tobacco's most potent addictive properties might well have exacerbated the public health problem, by inadvertently stimulating sales of ‘bad’ versions of the product, as sometimes occurs with alcohol content regulation [8,9]. It is not hard to imagine restrictions on the ingredients that make processed foods ‘hyperpalatable’ generating a similar response. Unfortunately, there does not appear to be a consensus view among public health advocates as to what ‘healthier’ processed foods might look like. It has been variously argued, for instance, that obesity prevention efforts should focus on calories [10], fats and sugars [11], refined carbohydrates [12,13] or on industrial processing in and of itself [5,14–16]. If the food industry is to be pushed, by regulation or public pressure, into developing healthier products, the development of clear parameters by which their products will be judged should become a priority of the research community. There is one sense in which reforming the food industry will be easier than the fight over tobacco. Although years of mandatory health warnings proved to be largely ineffective for tobacco, the same is not likely to be true for food products—as long as ‘healthy’ does not become synonymous with ‘unpalatable’. Consumers have a long history of gravitating towards healthy foods when quality has been easily discernable [5], and taxes or subsidies (which would probably be ineffective anyway [17,18]) are unlikely to be necessary. That the food industry uses modern technology to enhance sales is unsurprising. It is tempting to hope that restricting some of their more egregious practices will improve public health, and perhaps it would; but real change will come only when the public health community develops a clear vision of what efficiently produced healthy foods might look like. None.