London (CNN) Nearly 4 million children in the UK live in households that struggle to afford fruit, vegetables and other foods conducive to a healthy lifestyle, according to a report by the Food Foundation.

The report says the inability of low-income households to pay for healthy food increases the risk of obesity and diabetes, while also widening the gap in health inequality.

"The government's measurement of household income highlights the fact that millions of families in the UK cannot afford to eat in line with the government's own dietary guidance," said Anna Taylor, executive director of the Food Foundation, in a statement.

"It's crucial that a coordinated cross-government effort develops policy that accounts for the cost of its recommended diet, and creates a food system that does not consign those on lower incomes to the risk of diet-related illness."