The new "traffic light" system at the Cancer Treatment Centers of America in the Juniata section of Philadelphia is making it easier.
"It's a great system because all of us are familiar with red, yellow and green from everyday living," James said.
The system labels food the easy way - Red means stop because it includes foods high in fat and calories.
As for green...
"It's going to be your healthiest selections. They're full of vitamins, nutrients, antioxidants which helps protect your immune system," said Clinical Oncology Dietitian Nicole Kemp, R.D.
Kemp, who developed the system, says the green foods also include lean protein, which is vital for cancer patients who may unintentionally lose weight.
As for the yellow group: Slow down! Many are processed foods.
They do have some nutritional value but you don't want to do too much," Kemp said.
The system also helps caregivers. Thomas' wife says she's learned to make healthy changes in her own kitchen.
"More vegetables, more colors and less fat in it," Lois James said.
Kemp says the traffic light system has been a win-win, helping not only patients and caregivers eat healthier but also employees. They plans to expand the system to all their centers nationwide.