Americans spend millions of dollars every year on fad diets, crazy exercise plans, and complicated calorie-cutting methods to lose weight. But in fact, they key to shedding a few pounds (or more) is much less complex; all you have to do is start eating “green.”

That’s the upshot of a new book by Dr. Charles T. Nguyen, co-author of “The Thinsulin Program: The Breakthrough Solution To Help You Lose Weight And Stay Thin.” Nguyen argues the No. 1 culprit in weight gain and obesity is your insulin level.

High levels of the hormone cause the body to store fat, whereas low insulin levels cause it to burn fat.

So how can you keep your insulin levels low?

“If you eat green, leafy vegetables, the pancreas doesn’t need to produce insulin, so the insulin levels are lowered because there’s no fat, no carbs, in these foods,” Nguyen tells Newsmax Health.

Vegetables like asparagus, bok choy, spinach, kale, and arugula are prime examples of what Nguyen calls “green-light foods” that will absolutely lower a person’s insulin levels, and increase weight loss.

Of course, eating only vegetables would make for a pretty boring diet. Acknowledging this, Nguyen suggests adding a few “yellow-light foods,” which can raise insulin levels if not portioned correctly. These foods include fruits and nuts, which in moderation, are healthy components of a nutritious diet.

“In some fad diets, like the Paleo Diet, fruits are not allowed. This is wrong,” Nguyen notes. “Fruit will not spike insulin levels as long as you eat the right amount. The Thinsulin Program recommends fruits like apples, oranges, grapes, and any kind of berries.”

Proteins, too, are a good choice for keeping insulin levels low, especially those found in meats and egg whites.
On the flip side, you should avoid eating sweets and starchy vegetables, like potatoes, corns, carrots, and beets, because foods will spike insulin levels and cause your body to pile on the pounds.

As a result, Nguyen refers to such items as “red-light foods” that should be limited or eliminated from your diet altogether.

“Any type of grain will raise the insulin levels, causing weight gain,” Nguyen says, “regardless of how ‘healthy’ they may be.”

For this reason Nguyen also recommends staying away from beer, because it is made from wheat, which spikes insulin levels.

“Have you ever seen a wine belly? That’s because wine is made from grapes, a fruit that will keep insulin levels low,” he explains.

Nguyen adds that many low-calorie or extreme, restrictive diets involve “punishing oneself, and then rewarding oneself for trying.” But those yo-yo dieting approaches are doomed to fail.

“In order to beat this cycle of obesity, to really change it, we have to reject this idea of dieting,” he says.

“People looking to lose weight should look at it as a journey. In this way, people want to lose the weight, and understand that there will be little bumps in the road, but that they’re still getting where they want to go.”