12/03/2014 08:27 EST | Updated 02/02/2015 05:59 EST

Why Food Labelling Won't Lead to Sustainable Weight Loss for the Obese

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The Liberal government in Ontario has reintroduced The Healthy Menus Choices Act that will mandate caloric labeling. Restaurants, convenience stores, and others with 20 or more locations will be required to have menus and menu boards that include caloric content of standard food, beverage, and alcohol items and other information to be prescribed.

Caloric labelling is a recent strategy in combatting obesity. It's been tried in the United States in various cities and states. Its use is being extended nationally under the Patient Protection and Affordable Care Act (Obamacare). The idea behind requiring disclosure of calories of items on menus is simple: when people are alerted to how many each selection contains they will, thinking about their weight, select the ones with lower amounts. Does such disclosure work? To date: Not really.

Some studies reveal limited positive effects especially where lower calorie items are more prominently displayed and made easier to order. A very recent study claims that calorie labelling among a group of university students limited weight gain for the period of the study. However, overall, rigorous investigation methods (real world studies with a comparison group) reveal that caloric consumption is not reduced to the extent sought to be achieved by these labelling practices. Moreover, even for those individuals who did choose items with fewer calories, questions remain. Was the item chosen healthier? A diet soda will have fewer calories than apple juice, but it will not be the healthier option. When items with fewer calories were selected, was there compensation elsewhere? (I had a diet coke at the food outlet so I can have a chocolate bar later in the afternoon).

So should we have such labelling? Yes. But with our eyes open. Labelling is not going to lead to sustainable weight loss for the obese. It may help to prevent obesity under limited circumstances. It may also promote more nutritious eating/drinking as one part of an overall strategy to support healthier lives, especially for children. Caloric labelling is one aspect of the government's Healthy Kids Strategy. If that Strategy is implemented, supported with adequate funding, and rigorously monitored for effectiveness we could see some significant progress in terms of the overall impact of the strategies working in combination.

Something similar, in fact, happened in the battle against smoking. No one intervention brought down the rate. Instead a variety of legal strategies (banning sales to children, restricting advertising, mandating warnings, imposing high taxes etc.) working together significantly cut the numbers who use cigarettes. Also critical was a drastic change in public attitudes towards smoking: from a glamorous, sophisticated pastime to a filthy, expensive addiction. It took something like five decades but levels have dropped from about 50 per cent to about 18 per cent of the adult population.

One of the key principles of the Strategy is "health equity: ... interventions [should be] tailored to reach vulnerable populations most at risk". Being guided by that principle is critical. Obesity is not inevitably tied to poverty and marginalization but it can be closely related. In any event poor kids who are not obese can still need a lot of help to be healthy. The levels of child poverty and the use of food banks, including by children, in our society is grim. The Healthy Kids Strategy points in the right direction. We'll need to watch carefully to see where it and related initiatives take us.


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