We hear it around this time each year.
New year, new you.
But before you commit to a whole new diet and exercise routine, you may want to be aware of how several popular diets are made up of foods that can render your workouts next to useless.
Maxine Bentzel broke it down for us.
When Paolo Marin decided she was going to start exercising, she had one thing in mind.
"To lose some weight, for sure," Marin said.
And she's not alone. Personal trainer Wade Waddick works with people every day with the same goal.
"I would say 85-90% of people who walk through the door are yes, looking to lose weight," Waddick said.
But it takes a lot more than just exercise.
"We know that eating right and exercising is key to longevity," Waddick said.
And eating right is right up nutrition consultant Lily Maul's alley. She works with clients to teach them exactly what kinds of foods they should be eating.
"I think it's really important for you to fuel your body properly for the activity you have ahead," Maul said.
Maul said fad diets are popular because they promise and often produce fast weight loss.
"Everyone is talking about keto and everybody is talking about intermittent fasting," Maul said.
But Maul and others we spoke with have concerns about both.
The keto diet is high fat and low carb, which means it gives you energy to work out.
"Healthy fats give you a lot of energy," Maul said. "You should have enough energy to be able to work out."
But she and others warn that keto doesn't offer enough protein to build muscle effectively, which ultimately eliminates a lot of the effectiveness of exercise.
Maul said that intermittent fasting, while good for giving your digestive system a break every once in a while, doesn't properly fuel your body for a workout.
"As long as the quality of food that you're eating during the times that you are eating is high-quality food, it's giving you energy," Maul said.
And no food means no energy for a fully-functioning workout. Instead, experts suggest sticking to a diet that is high in protein and low in carbs. It's easy to follow and provides what you need for peak performance.
"If you're talking about longevity and you're talking about health and you're talking about aesthetics, I think you have to have the diet right before you can expect exercise to really give you the results and for you to see the results of exercise," Maul said.
So far, it's worked for Marin, who has lost 15 pounds.
"It really makes me feel a lot more energized in general," she said.
Speaking of being energized - remember, water is a workout and diet's best friend. You want to stay hydrated at all times and always avoid heavy foods right before working out.