Tom Violante makes it his business to know about food. He and his family have run Holiday Market in Royal Oak for nearly 60 years.

While he can have his pick of food choices inside his grocery store, Violante keeps to a very healthy diet.

"It is not so much what you eat but how much you eat," said Violante.

Violante eats the same foods every day. For breakfast he has skim milk with dry cereal, a banana, blueberries, strawberries and four prunes.  Lunch is a peanut butter and honey sandwich, a large glass of orange juice and an apple.

"For dinner, I had a small amount of protein or fish, which is protein, fish, meat, small amount, a good salad, fresh fruit, and a glass of red wine and that's it," Violante said.

Gail Posner, a registered dietitian, runs Healthy Ways Nutrition Counseling in West Bloomfield. She agrees with Violante that portion control is key.

"I like to encourage people to eat everything in moderation, but defining moderation is a key component," said Posner. "It means small, small portions."

When asked which foods she as a nutritionist would never eat, Posner said people should always avoid trans fats and to look for them on food labels.

"Trans fats can be very inflammatory to our health and cause a havoc of medical issues," said Posner. "Any inflammatory type diseases we think trans fats can be a big culprit in having those progress."

Posner highly recommends reading food labels when making decisions what to eat. Posner also said to avoid cereal with food coloring and cereals that have colorful berry-like things that have nothing to do with fruit.

"Stick with a natural, whole grain cereal. It's summer, add your own fruit," said Posner.

Another food to avoid is processed meat.

"The processed meats that I would avoid would be your high fats meats, like salami and bologna. These would be very high fat, filled with the bad saturated fats," Posner said. "These would also have the nitrates added to them."

Fish is good for you, but there is one Posner suggests people consider skipping.

"Swordfish is one of these really large fish that live a long time and they swim deep in our ocean. They collect mercury, a toxic substance," said Posner. "Mercury is an unhealthy substance for our body that can cause all sorts of health issues."

Maraschino cherries are another suggested no-no from Posner.

"Michigan is known for growing cherries and then you first put it in a bleach solution," said Posner. "So you take this vibrant red cherry and turn it into yellow and then you add high fructose corn syrup and add red dye to it. Why not just eat a real fresh cherry?"

A personal trainer shopping at Holiday Market said she recommends to her clients to shop the perimeter of their supermarket and stay away from the packaged foods.

"Stick to whole foods, real food, food that your grandmother would consider real food, like fruits and vegetables, and meats and fish and dairy and the things more on the outside of the supermarket, rather than some of the packaged stuff in the center," said Rachel Schey.

Posner said people don't have to completely stop enjoying good foods that might not always be good for you.

"I think people might say dietitians never eat dessert, or never have chocolate cake, or never eat potato chips. I am a dietitian and eat everything in moderation," said Posner. "So I am going to enjoy, on occasion, a small serving."

If you're going to indulge in something like potato chips, just don't eat them out of the bag. Posner said to read the label on the back and serve yourself one serving. Eat them slowly to enjoy them.

For more on Gail Posner and Healthy Ways Nutrition Counseling, click here.