By Jacque Wilson, CNN     Tue March 10, 2015

(CNN) When clients ask nutritionist Joy McCarthy for one easy diet change, her answer is always the same: Start cooking your own food.

“It’s completely transforming,” says McCarthy, author of “Joyous Health: Eat and Live Well Without Dieting.” “I often tell people, ‘Do you want to feel better? Do you want to have more energy?’ Because great health starts in the kitchen.”

Trust me: As a frequent restaurant patron, I feel your pain. But nearly every nutritionist I’ve spoken to has echoed McCarthy’s sentiment.

“There are so many reasons … ,” celebrity nutritionist Kimberly Snyder says before launching into a long list.

Here are the four big ones:

You’ll make better choices

Vegetables look much more appetizing when you’re standing in the middle of the farmer’s market than when you’re staring at a fast-food menu. Instead of being led by hunger – and glossy hamburger photos – you’ll choose more often what’s best for your body.

“That step of picking up your own food will cut out more and more processed foods,” Snyder says.

And healthier choices at the grocery store lead to healthier meals at home.

People who cooked meals at home at least six days a week consumed fewer calories than those who frequently ate out, a study published recently in the journal Public Health Nutrition found.

“When people cook most of their meals at home, they consume fewer carbohydrates, less sugar and less fat than those who cook less or not at all,” study author Julia Wolfson told the Johns Hopkins Center for a Livable Future.

You’ll eliminate the guessing game

Unless you’re BFFs with the chef, you probably have no idea what’s actually in that restaurant meal you’re eating.

Do they use olive oil or vegetable oil to cook the meat? Is there added sugar in the sauce? What about food coloring? Is the spinach organic or covered in pesticides? How much salt is in that soup?

Cooking at home eliminates the guesswork. It also eliminates the chance that your food will contain an allergen or ingredient that could make you sick.

Think about it this way, McCarthy says: You’re not going to go to a gas station that doesn’t label its pumps, and put diesel into a car that takes premium gasoline. “But humans do that all the time. We put the wrong fuel in all the time.”

You’ll eat more mindfully

Eating has become just another chore on many people’s to-do lists, Snyder says. “Get your shoes shined, pick up the dry cleaning, order food.”

Cooking opens your eyes to not just what’s in your food but also how you eat it. After all, who makes a six-layer lasagna from scratch and then eats it while zoned out in front of the TV?

Eating mindfully means you savor each bite and recognize when you’re full – both of which aid digestion, Snyder says. Sitting down to regular meals with friends or family can also help improve your relationships.

“Cooking brings you back to a nurturing home space. It creates an environment that’s supportive and helps you fight stress,” Snyder says.

You’ll find it’s easier than you think

“If you can read, you can cook,” McCarthy says. “I don’t think you need talent because there are so many amazing cookbooks out there.”

Start simply – with a breakfast smoothie or one dinner a week. Then build up your repertoire. Though you may dream of mimicking your favorite “Top Chef” techniques, grilling a few chicken breasts and steaming broccoli is fast and nutritious.

“The simplest foods are the healthiest,” Snyder says.