Families have cut the number of calories they purchase but are buying different, more energy-rich, comestibles

This article is more than 6 years old

This article is more than 6 years old

Troubling trends in British eating habits emerge in two Institute for Fiscal Studies analyses presented at the Festival of Social Science.

The first study analyses more than 30 years of official data on England, and confirms that spending on soft drinks, eating out and snack food have all increased over that time.

Intriguingly, however, the average total number of calories being purchased has declined.

The implication is that rising rates of obesity are better explained by declining levels of physical activity, rather than overeating.

The second study, which covers the UK as a whole, looks in more detail at changes since the recession began in 2008.

In the face of squeezed budgets and rising prices, it finds families have reduced real food expenditure by 8.5%, continuing to cut the number of calories purchased, but also spending less on each calorie.

This has involved buying different – more energy-rich – forms of food. Changes in purchasing patterns include a drop in spending on fruit and vegetables, and an increase in processed foods.

More sugar and saturated fat is being purchased and summary measures of nutritional quality have declined.

These trends appear to be concentrated on families with children, and have continued – and if anything, accelerated – after the technical recession ended in 2009.

Kate Smith, one of the authors of the second report, said families had responded to squeezed incomes by switching to cheaper calories. She added: "This has coincided with a fall in the nutritional quality of foods purchased."

Martin O'Connell, another author, said: "Links between food purchases and diet-related health problems such as obesity are complex.

"Understanding these links involves considering other aspects of people's lifestyles and the influence of economic conditions on people's decision-making."