Who doesn't love a good celebrity health secret? It doesn't matter if it's a crazy cleanse or a tortuous bootcamp. If it's good enough for the celebs, it's good enough for us. A recent study published in Systematic Reviews examined how the rich and famous encourage us to live healthier. "Celebrities are highly influential people whose actions and decisions are watched and often emulated by wide audiences," wrote the author. "Many celebrities have used their prominent social standing to offer medical advice or endorse health products, a trend that is expected to increase."

So, if you need a little motivation to make healthier choices, check out what some of your favourite stars do to stay slim, trim, and beautiful.

Jennifer Lopez doesn't drink, smoke, or consume caffeine

In addition to wearing plenty of sunscreen, Jennifer keeps her complexion clear and glowing by avoiding cigarettes, caffeine, and alcoholic beverages. "I don't drink or smoke or have caffeine," she told Us Weekly. "That really wrecks your skin as you get older."

Reese Witherspoon saves indulgent foods for special occasions

The Nashville native loves fried chicken, biscuits, and other high-calorie southern dishes, but tries to save those foods for parties and special get-togethers only. In her day-to-day diet, she opts for veggies and lean protein.

Martha Stewart gardens in her free time

The 75-year-old lifestyle guru spends much of her free time in the greenhouse and yard. Not only is it a fun way to burn calories and de-stress, it's also a way to ensure she has access to healthy and organic fruits and veggies. "I make [my green juice] out of vegetables that I grow," Martha told in an interview. "I grow in the greenhouse in the winter and the garden in the summer. And they're organic vegetables."

Cher works out five times a week

"I exercise about five times a week because it's something I've always done and I just enjoy it," she told Hello! The singer also makes her fitness routine fun with activities like surfing, walking, and playing Wii Tennis.

Halle Berry manages her diabetes by eating four small meals a day

Since Halle was diagnosed with diabetes at just 19, she has made significant lifestyle and eating changes. "My diet is geared towards managing my diabetes, so I try to eat four small meals a day. I like to feel strong and healthy," Halle told Women & Home South Africa. Now she makes an effort to eat lots of veggies and drink plenty of water while avoiding processed sugars and bread.

Jennifer Aniston eats her favourite comfort foods – but with better ingredients

Besides working out, practicing yoga, and trying to eat a balanced diet, Jennifer makes an effort to enjoy her favourite dishes in healthier ways. For instance, she'll make a homemade version of lasagna, but swap out pasta for veggies.

Julia Roberts works with a nutritionist

With the help of nutritionist Carrie Wiatt, Julia approaches eating in a balanced way. Carbs aren't off limits, but she tends to go for veggies, protein, and healthy grains. Breakfast usually consists of homemade granola, berries, and yogurt. Lunch is often spinach filo pie with wheat pilaf. And dinner tends to include salmon, quinoa, and veggies.