Eating a vegetarian diet rich in fruits, vegetables, and grains is not only good for you, it's also more affordable then other healthy dietary patterns if you're buying online, according to new research being presented at this year's European Congress on Obesity (ECO) in Vienna, Austria (23-26 May). On average, following a vegetarian diet costs around $2.00 less per day than the Mediterranean and the US?healthy diet.

Federal dietary guidelines reveal that around three-quarters of Americans do not eat enough fruit, vegetables, and dairy, and most exceed recommendations for added sugars, saturated fats, and salt. About half of all American adults have one or more preventable, diet-related chronic disease such as overweight/obesity, cardiovascular disease, and type 2 diabetes. How to get people to eat more healthily at an affordable price is often a hotly debated topic. But, how much does it actually cost to eat in a truly healthy way?

To answer this question, Dr Hilary Green from the Nestlé Research Center in Lausanne, Switzerland and colleague Gary Sweeney compared the cost of following 2?week menu plans for three healthy eating patterns: a vegetarian diet, the Mediterranean diet, and the US?healthy diet, all of which were aligned with the 2015?2020 Dietary Guidelines for Americans. [1] All food and beverage items were sourced from the online food?shopping platform Amazon Grocery and Gourmet Food which captures 26% of the US online food and drinks market.

Food and beverage items from the three different 2 week?menu plans were assessed for nutritional quality using the previously-published Nutrient Balance Concept that assesses the overall nutritional quality of meals composed of multiple food items as well as that of total diets. The researchers collected the cheapest food and drink prices from Amazon excluding online sales, discounts, and deals. Prices were converted from the online advertised US$/item or US$/ounce to US$/gram. They also calculated the food group cost because the US dietary guidelines are based mainly on food groups.

Results showed that the average nutritional quality scores of all three dietary patterns were similar--vegetarian 85.3; US?healthy: 84.3; Mediterranean: 82.4. However, the vegetarian diet was found to be significantly more affordable than the Mediterranean menu plan. The average cost for each menu plan ranging from US$15.4 per person per for the vegetarian diet, to US$17.0 per person per day for the US?healthy diet, and US$17.3 for the Mediterranean diet.

Although substantially less meat and poultry were used in the vegetarian menu plan, the authors note that, "this did not affect nutritional quality and may have contributed to making this the most affordable menu plan." Online grocery shopping sales in the USA generated an estimated $US 7 billion in 2017, and are predicted to reach almost $US 30 billion by 2021. Currently, around a third of Americans buy their groceries online.

Dr Green concludes: "Online shopping makes it convenient to buy foods for a nutritious diet that meets government recommendations, but it may be expensive. Even though a vegetarian menu plan may be more affordable than other healthy menu plans, $15.4 per day per person is still expensive. The United States Department of Agriculture has previously estimated that the daily cost of food for a healthy menu plan can be as little as $6.5 per day."

The authors note some limitations including that the pricing was done on menu plans that were developed only for one consumer profile--a woman aged 40, not pregnant, and not lactating. A different consumer profile, or a different choice of foods would affect the overall cost. The primary goal here was to meet the 2015-2020 US dietary guidelines, without any limitations on cost.

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