Some people are motivated to do things because it helps them, personally. If eating healthy is good for them, then they will do it. No questions asked.
Other people still struggle to be motivated, even if they would experience the same benefits. It isn't hard to understand why: if someone has learned to live with the body and state of health they've got, then the only thing that really scares them is getting worse.
When was the last time you ran a mile? Yesterday? Last week? Last year? Last decade? Unless you run a lot, it is easy to let that ability get away from you. How often does the average joe need to run a mile in his day-to-day life? Not at all, really. But even if you don't feel it, you are getting worse and worse at running everyday that you don't do it.
But if you don't run, you'll never realize how much you've lost. This applies to all health situations. You don't realize you can't bend down anymore until you have to. You don't realize you can't play catch with your kids until your shoulder cries out in pain.
It's hard to motivate ourselves to avoid those things, because we only notice them after they are a problem. But just treating current problems is no way to take care of yourself, you have to avoid health problems to feel really good.
So try this: meditate and be mindful for a few minutes about the well-being of your loved ones. Consider the positive effect if would have on the people around you if your mood was improved through regular meditation. Or the effect that improved strength and flexibility will have on the time you spend with your kids and/or grandkids. Or the effect that better sexual health will have on your love life. Or the effect that lower health care costs and insurance premiums will have on your family's quality of life.
The list goes on and on, but the theme is always the same: your health is not just about you, it is about everyone around you, and everyone who cares about you. So if you aren't motivated to improve your health and start a mind-body routine for just your own benefit, consider the benefits it will have on the people around you.