Jack LaLanne, an advocate of regular fitness and healthy eating for seven decades, gave advice that was ahead of its time, experts say. While it seems many nutrition and fitness fads come and go, LaLanne's advice, which promoted weight lifting and eating fruits and vegetables, has withstood the test of time.

And his strict fitness regimen may have kept him in peak physical condition well into his elder years. LaLanne died Sunday at the age of 96.

"He was a fitness person before fitness was fashionable," said Katherine Tallmadge, spokeswoman for the American Dietetic Association.

Some say LaLanne was the first modern professional fitness instructor, promoting exercise for anyone and everyone rather than just athletes, said Neal Pire, a personal trainer and president of the fitness company Inspire Training Systems.

"You can't take one case of a person and apply it to everyone, but it's just wonderful to know that how he lived probably did contribute to the high quality and longevity of his life," Tallmadge said.

Here, the experts explain why five tips that LaLanne long-advocated are still true today:

Eat more fruits and vegetables

LaLanne touted eating more fruits and vegetables long before Amerians were familiar with the "5-a-day" public health message. Studies over the past several decades have further corroborated the importance of eating fruits and vegetables, Tallmadge said.

"It's one of the simplest things people can do to transform their health and their lives," said Tallmadge, who also authored "Diet Simple" (Lifeline Press, 2002).

"We know now that people who eat at least five cups [of fruits and vegetables] a day have lower blood pressure, lower cardiovascular disease, lower rates of cancer, they have a better immune response, usually they're leaner and have lower rates of diabetes and obesity," she said.

This message hasn't faded away because there is myriad research to back it up.

"A lot of fads aren't based on science," Tallmadge said. "They're based on gimmicks designed to get people to buy diet books or special foods or supplements," she said.

"But eating more fruits and vegetables has stood the test of time because it's been proven by science."

Exercise, no matter what your age

LaLanne promoted exercise for everybody, even the elderly and the disabled.

"It's never too late to start," was LaLanne's message, Pire said.

And recent studies have shown that, even in your 80s and 90s, resistance training can still make muscles stronger, Pire said.

"An old muscle isn't a muscle ready for retirement, it's the same as any other muscle, and it can get stronger," Pire said. "LaLanne was advocating that before there was any research," he said.

Weight lifting

LaLanne was an advocate for weight lifting , even for women, who at the time were not thought to benefit from weight lifting, said Karen Croteau, a professor in the department of exercise, health, and sport sciences at the University of Southern Maine.

There are many benefits of weight lifting, Croteau said, including increasing strength, which helps to carry out daily activities and prevent injury. It also helps to maintain lean muscle mass even while dieting, Croteau said.

Use simple equipment

LaLanne believed in using simple equipment, such as a broomstick, chair or anything that provides resistance to motion that the body can overcome, Pire said.

This strategy makes exercising more accessible to the public, Croteau said. "[It] means people can do it at home only so many people will go and join a health club,"

"Making any type of physical activity more accessible makes it more likely to get completed," she said.

Use it or lose it

One of LaLanne's main messages was: "The only way you can hurt the body is not to use it," Pire said. This mantra is in line with something we are just beginning to realize: that inactivity is a killer, he said.

Daily exercise now has proven health benefits, Croteau said. "Consistent physical activity helps with blood pressure, helps with body weight, helps with lipid levels like cholesterol, [and] helps with blood glucose levels," Croteau said.

The key to the endurance of LaLanne's advice may have been its simplicity, Pire said.

"It was about moving the body and being physically active," Pire said. "It wasn't about lifting the heaviest weight. It was really all about enjoying movement," he said.

Pass it on: Fitness guru Jack LaLanne advocated health messages that have endured and have been held up by scientific findings, experts say.

Follow MyHealthNewsDaily staff writer Rachael Rettner on Twitter @Rachael_MHND.