Protein-packed meal and snack ideas Megan Fox's trainer recommends for his celebrity clients

• Celeb trainer Harley Pasternak helps plan diets for stars like Megan Fox, Ariana Grande, and Rihanna.
• He has clients eat three meals and two snacks a day, full of protein, fiber, and healthy fats.

Good nutrition is the key to building a Hollywood physique, according to Harley Pasternak, a celebrity trainer whose clients include Megan Fox, Ariana Grande, Rihanna, Kim Kardashian, and Halle Berry.

In addition to designing intense 20 minute workouts for famous clients, Pasternak is also a nutrition expert and author of several books on healthy eating, including the recently updated "Body Reset Diet."

"For my clients, we focus on protein, fiber, and healthy fats, three meals and two snacks a day," he told Insider as part of a promotional event with the no-sugar dairy company Maple Hill Creamery.

Pasternak told Insider a simple hack for building a balanced plate at mealtimes and shared his favorite ideas for healthy snacks.

Use your hand size to measure proper portions of protein, carbs, and healthy fats

Portion sizes and a balanced plate are crucial for healthy eating. Pasternak said you can use your hand to figure out how much food to include in each meal, without having to get out a food scale or other measuring tools.

For protein, aim for a serving of lean meat, chicken, fish, or tofu that's about the size of your hand. Then, add a palm-sized portion of fiber-rich carbohydrates, such as legumes or fruits like berries and citrus. Add healthy fats, which are crucial for keeping you satiated after a meal, in the form of nuts, seeds, olives, or avocado, measuring a serving about the size of your thumb.

Finally, round out the meal with as many veggies as you want, including leafy greens, tomatoes, peppers, cucumber, and asparagus.

Go-to healthy snacks include yogurt parfaits, baked apples, and veggies with hummus

Pasternak's nutrition plan for clients includes two snacks a day, sticking to the same principles of protein, fiber, and healthy fat as his meal plans.

He said one of his favorite high-protein snacks is a parfait of Greek yogurt and berries, topped with nuts and seeds or even a bit of peanut butter.

Another simple snack is hummus with a selection of veggies to dip, including peppers, carrots, cucumbers, even raw asparagus or mushrooms.

For a sweet treat between meals, Pasternak recommends baked apples.

To make it, core the apples and place them on a tray with a little water and a stick of cinnamon in the center of each apple. Bake for about 15 to 20 minutes. Once the apples are done, add a little Greek yogurt mixed with cinnamon to the center of the apples before digging in.

"It's just like dessert," he said.