Fitness experts say to see results it takes 20 percent of your workout and the rest comes from a healthy diet. Two of the most popular diet trends right now are the ketogenic and paleo diets.

So, which one works the best?

KNXV took the two diets to a certified nutritionist. Judy Nicassio with Rejuvena Health and Aesthetics in Scottsdale, Arizona says the keto diet works faster and most people see results quicker. However, the drawback is that it is a difficult lifestyle to maintain. That’s one of the reasons Nicassio prefers the paleo approach better.

The ketogenic diet focuses on low carbohydrates and high proteins and fats. It requires a lot of preparation to stick with the food choices. The idea of it is your body is burning fat instead of the carbs for fuel.

The paleo diet is a lot of meat, seafood, fruits and vegetables. The paleo diet is meant to harken back to the eating habits during the Paleolithic era. One would only eat food available at that time — which was mostly fresh fruits and vegetables.

There are some side effects dieters should know: 

Going on keto could make you think you're sick. It’s called the "keto-flu." There are symptoms you may experience when you first start the diet such as fatigue, sweating, chills.

This can happen while your body adjusts to having so little carbs. Nicassio says those on keto also may find it easier to get dehydrated so they’d need to up their water intake.

Those on paleo could be at a higher risk of calcium and vitamin D deficiencies. It’s recommended to always consult with a doctor to see which diet will be the right fit.