In 2015, Jennifer Lopez shared her food diary with People magazine. A typical day looked like this: breakfast was a smoothie with a nutritional powder and berries, yogurt, lemon juice, and 1/4 tablespoon of honey; for lunch a kale salad with queso, pumpkin seeds, lemon juice, and 3 tablespoons of olive oil; an apple as a snack; and dinner served skinless grilled chicken breast with 1/2 cup sauteed Brussels sprouts and 1/2 cup baked yam. For dessert, she had a chocolate chip cookie.

Total calories: 1,392.

“I don't deprive myself,” Lopez declared. One of her tricks? "I always have healthy snacks like fruit and vegetables with me."

Keeping track of what you eat and drink day-to-day is a powerful boost to any effort to shed excess pounds or maintain a healthy weight. And you don't have to be perfect.

According to a new study conducted by researchers from the universities of Connecticut, Florida, and Pennsylvania along with Weight Watchers, if you track around 30% of your days over six months, you will lose about 3% of your body weight.

Keep a written record of 40% of your meals and you'll lose around 5%.

And if you log 70% of your daily food intake, you're on track to lose 10% of your body weight.

That's a clear demonstration of how logging your food intake reinforces your commitment to achieving and maintaining a healthy weight.