Professor Mary L’Abbé, chair of the Department of Nutritional Sciences and senior author on the study (photo courtesy Faculty of Medicine)

Salty surprise: fast food beats table service

But sodium levels "alarmingly high" in all chain restaurants

The first-ever systematic study of sodium levels in Canadian chain restaurants shows sodium levels are off the charts — but the worst culprits aren't fast food chains.

They're the restaurant chains with table service.

A University of Toronto study of foods from 85 Canadian chain restaurants found that on average, a single menu item (such as one hamburger, sandwich or stir-fry) from a sit-down establishment contained nearly 100 per cent of the daily recommended amount of sodium. Side dishes contained nearly 50 per cent.

Food from fast food chains contained, on average, less salt. But single menu items still packed a whopping two-thirds (68 per cent) of the daily recommended amount of sodium.

“We expected sodium levels to be high, but we didn’t expect them to be as alarmingly high as we found in the study,” said Mary Scourboutakos, a PhD student in U of T’s Department of Nutritional Sciences, and lead author of the study.

“These findings demonstrate the need for a population-wide sodium reduction strategy to address the high levels of sodium in Canadian restaurant foods.”

Limiting salt intake is important because high dietary sodium is a risk factor for hypertension, which is the leading preventable risk factor for death worldwide.

Scourboutakos’ team collected nutrition information from chain restaurant websites in 2010 and 2011 and analyzed 4,044 meal items. Sodium levels were compared to the daily adult adequate intake level of 1,500 milligrams and the tolerable upper limit of 2,300 mg per day.

The study found that a single meal item with no side dish from a sit-down restaurant (such as a hamburger, sandwich or stir fry) contained on average 1,455 mg of sodium per serving, while fast food meal items contained 1,011 milligrams. Side dishes contained, on average, 736 milligrams of sodium.

As many as 40 per cent of sit-down restaurant meal items exceeded the daily tolerable upper limit for sodium — and that doesn’t include the side dishes that would normally be consumed with a main dish.

“This study is important as Health Canada has not yet set targets for restaurant foods — a major gap in our Canadian sodium reduction efforts,” said Professor Mary L’Abbé, Chair of the Department of Nutritional Sciences and senior author on the study.

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