Abstract
Background: High sodium intake is a well-known risk factor for high blood pressure, the leading preventable risk factor for death worldwide. Sodium intake in the New Zealand population is well above what dietary guidelines recommend. Fast foods may be a large contributor to sodium intake, given that they are a group of foods typically high in sodium, and are known to be frequently consumed by some population groups in New Zealand.
Objective: The overall aim of this study was to determine and compare the sodium content (per serve, per 100 g and per 1000 kJ) of commonly consumed fast foods (from independent outlets and large chain restaurants) in New Zealand, and to discuss these results in light of current public health recommendations for sodium intake. A further aim was to estimate the mean intake of sodium from savoury fast foods for the adult New Zealand population.
Design: Commonly consumed fast foods in New Zealand were identified from results of the 2008/09 New Zealand Adult Nutrition Survey. The top twelve most commonly consumed fast foods from independent outlets (n=52) were selected to be tested analytically in the laboratory, while the sodium and energy content of all savoury fast foods (sixteen food types) from large chain restaurants (n=471) were collected from online Nutrition Information Panels. Linear regression was used to test for significant differences in the sodium content (mg/100 g, mg/serve) of fast foods by brand. Descriptive statistics were used to compare results between and within food categories, and with current public health recommendations for sodium intake (New Zealand/Australia Sodium Nutrient Reference Values, and the 2012 United Kingdom Food Standards Agency sodium targets). The mean daily sodium intake from savoury fast foods was estimated using sodium values from this study, and from sodium values contained in the New Zealand food composition database.
Results: From independent outlets, a single sausage roll or beef hamburger provided 55% and 50% of the daily sodium Upper Limit (2300 mg/d), respectively. Per 100 g, sausage rolls were the highest in sodium, and a meal of chop suey had the highest sodium per 1000 kJ. Ten of the twelve fast foods exceeded the maximum United Kingdom Food Standards Agency 2012 sodium targets. From large chain restaurants, a single burger or serve of pizza provided 45% and 55% of the daily sodium Upper Limit, respectively. Per 100 g and per 1000 kJ, sauces/salad dressings and fried chicken had the highest sodium content. Twelve of the thirteen fast foods exceeded the United Kingdom Food Standards Agency sodium targets. Significant differences (p<0.05) in the sodium content by brand were found for burgers, pizza, sandwiches/wraps, and fries/wedges. The mean intake of sodium from savoury fast foods was estimated to be 283 mg/d amongst the total population, and 1229 mg/d amongst fast food consumers.
Conclusion: The majority of commonly consumed fast foods in New Zealand exceeded recommended sodium limits, and provided a large contribution to daily sodium intake amongst fast food consumers. This study supports the need for a population sodium reduction strategy, which should include reformulation, as well as consumer education, improvements in food labelling, and setting of population sodium reduction targets. This approach has the greatest potential to reduce sodium intake of New Zealanders, and prevent significant morbidity and mortality in future years.