Sometimes the foods we think are the healthiest can be deceiving. Jackie Warner, star of the Bravo reality series Work Out, suggested really looking at the foods you are eating.

"I love fruits and you should be eating a lot of fruits, but for someone who is really trying to lose weight, you want to eat fruits that are low in sugar,” Warner said. “And a banana has a lot of sugar calories.”

A medium sized banana has about 12 grams of sugar. Some alternatives include apples, berries and citrus fruits.

Click here to watch Jackie Warner discuss this on video.

Yogurt is another snack that can help sabotage your diet, Warner said.

"It’s got calcium, vitamin D and guess what else it has - 22 grams of sugar,” Warner said. (That's roughly the amount of sugar that is in a candy bar).

"Fat does not make you fat,” Warner said. “It's sugar and calories that make you fat. Period."

Warner also said to never eat any food that contains eight grams of sugar or more.

To really see results Warner warns that you must be a smart shopper and watch out for deceptive packaging. With a package of cookies in hand, Warner pointed out that you should look at how many servings are in there. The packaging says "only 100 calories" but that's for just one cookie — there are three in the pouch.

Alcohol could also be making you fat, she said. But Warner said you don't have to give it up all together.

"If you're drinking two glasses of wine per night, go down to one,” she said. “I'm not about deprivation.”