The Keto diet gets lots of attention for weight loss. This cardiologist says it's still not good

The Keto diet gets a lot of attention, eating lots of fat and no carbs to lose weight, but a cardiologist says it's a bad idea. 

U.S. women's soccer star Alex Morgan is many things besides a tremendous athlete. She's passionate about animals and because of that she is a vegan, meaning she eats no meat or dairy. She's got plenty of company among elite athletes.  

The guy who just won Wimbledon, Novak Djokovic, doesn't like the vegan label but he praises his plant-based diet for helping him work his way to the very top in the tennis world. 

"Most of the acquired disease, heart failure, heart attack these are things we can prevent by changing our nutrition," cardiologist Dr. Kim Williams says.

The doctor says there's no big secret. The answer is plants. 

He helped to coauthor "The Nutrition Guidelines" for the American College of Cardiology and here's the simple version: cut way back on foods high in saturated fat, sodium and sugar while eating way more fruits and vegetables. 

"Part of it is what I call a substitional benefit. You're taking away something terrible that plugs arteries, promotes plaque and you replace it with something that's healthy for you." 

 Dr. Williams got a lot of attention recently by proclaiming no one should be doing the keto diet, a diet that typically involves a lot of fat. Think meat and cheese, while cutting out carbs. The doctor admits there are some benefits, but they're not worth the risk. 

"You'll find people who lose weight, diabetes is better - but the cholesterol has tripled. And then they'll need our services - heart attacks and cardiac events - it's well versed in the literature." 

But, what if you want to lose weight, or you're trying to ease your way into a healthier lifestyle? Doctors says work on replacing processed meats, red meat and even chicken with plants. 

"If you're really motivated to lose weight, do the plants,"

In fact, one study says a man on a plant-based diet will live 9 years longer. 

"But I don't think that's all of it, it's how healthy you'll be, less disease and less healthy care, something we're all very sensitive to," he said. 

There's a lot of good advice on how to make good nutrition easier online at