Need some thinspiration in order to fit into your bikini this summer? Bob Harper has you covered!

Us Weekly asked The Biggest Loser trainer -- and author of the new diet book The Skinny Rules (out now) -- for his top five tips to slim down just in time to hit the beach.

"I've been working on The Biggest Loser for a long time, and what I realized was that people need guidelines -- they need a To Do List," says Harper, who appears on NBC's series opposite Dolvett Quince. "And I'm really good at giving people orders."

Inspired to put his expertise in writing when Ben Ward, the husband of season 11 winner Olivia, asked him for menu planning advice, Harper, 47, confirms anyone can follow his tips -- whether they've got 20 pounds or 200 pounds to lose.

The ultimate must on Harper's Skinny Rules To-Do List? Be sure to stay hydrated in the summer months. "Water is a miracle fluid," the trainer says, suggesting that 12 ounces of water be taken in before every meal. In addition to revving up your metabolism, the added water will keep you from over-eating.

When it comes to menu planning, Harper confirms that protein is key: "Eat it at breakfast, lunch and dinner," he tells Us.

For more from The Biggest Loser's Harper -- including why he thinks it's so important to treat yourself to a 'splurge meal' every now and then -- watch the exclusive video above now!