He told delegates at the Hospital Caterers Association (HCA) forum in Wales: "Unlike schools and prisons, there are no mandatory minimum requirements for hospital meals, so the next Labour government will substantially increase investment in our NHS to improve patient care including providing the nutritious meals patients deserve.
"Quality care is about more than bandages and medicine, it's about quality nutrition, so let’s pay tribute to you for the part you play in every illness defeated, every life saved. I believe that food definitely is the best medicine."
He said that both obesity and malnutrition were serious problems that were getting worse, and they had an impact on the NHS budget because of the cost of treating the consequences. On top of that, the UK population is ageing and it means a greater call on scarce resources.
To tackle these issues he said Labour would be adding funding to the NHS - a likely £5bn a year plus a one-off £10bn to encourage investment in infrastructure.
He added: "The next Labour government will put hospital meals for patients, staff and visitors on the same footing as schools and prisons, with independently monitored and enforced food standards.
"We think it will reduce obesity, help patients recover more quickly.
"All food served from NHS premises should be healthy. Hospitals are no place for sugary foods, fizzy drinks and super-size servings. When we have a burger bar at the entrance to Addenbrookes [leading cardiac hospital] then it shows we still have a long way to go."