Many people find that they're hitting their stride around age 35. But the body has other ideas, because that's when gradual loss of muscle mass begins.

People typically experience a 1% to 2% loss of muscle annually up to age 60, then it accelerates to around 3%. This creates a condition called sarcopenia.

And while it is lost, people often substitute fat for muscle mass. That increases the risk for chronic health problems.

For example, a recent study found that those who have excess fat on their arms are 18% more likely to develop Alzheimer's and Parkinson's than people with low levels of fat in that area.

But you don't have to accept the slow erosion of your strength and accumulation of excess fat. Here are three things you can do:

1. Get enough protein. A meta-review of studies concluded that older adults should eat more than the recommended amount of protein to counter muscle loss. The researchers suggested a 180-pound man eat 82 grams to 130 grams daily.

2. Do strength training (using resistance bands, your body weight, dumbbells, or weight machines) three to four times weekly.

3. Enjoy high-protein snacks and muscle-building supplements. Nuts, peanut butter, chia seeds, and edamame satisfy hunger and help build muscles. Creatine — an amino acid made from arginine, glycine, and methionine — doesn't build muscle itself, but along with resistance training and a healthy diet, it may offset muscle loss, according to Harvard Medical School.