Children really do learn by example, so if you're not eating healthfully and exercising, it will be that much tougher to get them to improve their habits. They might feel isolated and resentful if they're made to nosh on carrot sticks while Dad munches on cheese puffs.

Try incorporating physical activity into family time, say, by taking a group walk after dinner. Find out which sports and games your children really like and encourage them. Make healthier meals and snacks for the entire family and eat them together whenever possible, since research suggests that doing so also lowers obesity risks. You might not need to give up all your favorite family recipes. Instead, consider substituting some ingredients, say, olive oil instead of butter, ground turkey instead of ground beef, and nonfat sour cream instead of the full-fat version.

Read more on the 6 ways to help your child maintain a healthy weight, take a look at our best tips for putting together healthful meals for less, and for fitness advice for the whole family, see our DIY Guide to Exercise & Dieting.