Registered dietitians dish up their best advice for staying fit and healthy for decades to come.

As you’ve ventured into your 40s, you may have noticed that your energy crashes more quickly than it used to. Or maybe you’ve gained a few kilos around your middle—despite the fact that your diet has remained basically unchanged for as long as you can remember.

It’s not your imagination. As women near their 40s, basal metabolic rate decreases, oestrogen levels dip and blood vessels decrease in elasticity. These factors make it harder to stave off belly fat, and also increase the risk of heart disease, cognitive decline, and osteoporosis, says nutritionist Maggie Moon. “The good news is that what we eat—something we all do each day—can make a big and lasting impact.”

Here, 10 simple tweaks you should make to your diet in your 40s that can help you stay lean and healthy—for life: