Low-income households need to spend a third of their weekly income on food if they want to eat a healthy diet, a new study from Northern Ireland has claimed.

The research, commissioned by the Food Standards Agency NI, the Consumer Council and Safefood – the food safety body for the Republic of Ireland and Northern Ireland – found a healthy food basket for a family of four cost £119 a week, while a pensioner living on their own would have to spend £59 per week.

The average weekly take-home income in Northern Ireland is £338 for a family of four where both parents are on Jobseekers Allowance and £415 for a four-person family with one parent on the national minimum wage; it is £164 for a pensioner on a State Pension.

To calculate the cost of a healthy diet, researchers put together food baskets (using feedback from consumer focus groups) that offered a “socially acceptable” choice of products for different types of household while meeting healthy eating and nutritional guidelines, as defined under the UK Eat Well Plate. The goal was to create baskets that were “realistic and acceptable” as well as “nutritionally adequate”, the researchers said, and took account of luxury items such as alcohol, treats, takeaways and Christmas products in order to offer a realistic picture.

Prices were then primarily taken from the Tesco online grocery website to calculate overall cost (see further details below).

Meat was the most expensive part of a healthy diet for a four-person family, accounting for 25% of spend, the calculations revealed, but for a pension living alone fruit & veg was the most expensive. Dairy products, eggs, and breads were the groups accounting for the next biggest chunks of food spend.

The research was conducted by the Vincentian Partnership for Social Justice and involved nutritionists from Ulster University. It forms part of a wider research effort into food poverty in Northern Ireland under the Food Poverty Network.

“For the first time, we have sound evidence on the real cost of an essential food basket and how food issues relate to poverty and economic hardship,” said Sharon Gilmore, head of standards and dietary health at the FSA in Northern Ireland. “We need to take this evidence and develop an action plan to tackle food poverty in Northern Ireland.”

Dr Cliodhna Foley-Nolan, director for human health and nutrition at Safefood, said the consequences of food poverty could be dramatic. “On a longer-term basis, the health consequences for those households living in food poverty are higher rates of diet-related chronic diseases such as osteoporosis, Type 2 diabetes, obesity and certain cancers. In trying to make a limited household budget go further by compromising on healthy foods, some households are ending up nutritionally poor.”

Pricing methodology

To cost the food items in the healthy food basket, the researchers used Tesco prices as listed on tesco.co.uk during the week of 3 November 2014. However, they chose not to take into account special offers or discounts and excluded the cheapest own-label items, sold under Tesco’s Everyday Value brand.

Everyday Value was “by and large the cheapest Tesco brand”, the researchers acknowledged, but said: “In order to allow choice, people should not have to buy the cheapest item possible and that is why the Everyday Value brand was not selected.”

However, the researchers said families recognised the value offered by promotions. “While special offer items were not priced during this pilot study, participants in the family focus groups mentioned that special offers can make a difference and can be of benefit to families.”

Pensioners, on the other hand, did not see special offers as offering good value because they were typically targeted at bigger households.

As for meat, consumers in Northern Ireland were “very clear they did not want to buy cheap meat”, the researchers said in their report, adding the meat was therefore priced based on local butcher’s shops rather than supermarkets.

To reflect convenience shopping habits, milk and bread prices were based on prices in a local Spar rather than Tesco.

Furthermore, the calculations included food for visitors, accounting for 16.9% of total weekly food spend for a pensioner living on their own. The researchers stressed their calculations were based on what people should be able to afford rather than what they could actually afford, and said the fact pensioners deemed food for visitors important showed it was a vital part of social inclusion. “This food basket…clearly demonstrates that members of the public believe that a food basket should include more than just the necessities to sustain people: it should also allow pensioners living on their own to have a standard of living that enables them to participate in society.”