A leading nutritionist says increasing food costs could be harming people's general health.

New figures from Otago University's human nutrition department show it costs $50 more per week than five years ago to feed a family of four with the basics.

Associate professor Winsome Parnell says with the recession and the fact it is winter, means a lot of people have less disposable income to spend on food. She says that raises concerns about whether people are even spending the recommended amounts to meet their nutritional requirements.