Fat people who are lazy gluttons have debauched themselves on a life of food.
To them food is their only reason to live.
To keep your wife and children from becoming fat and obese you may have to avoid desserts and eat only those foods which are healthy and good for you, and only in reasonable sizes.
Do not go out to restaurants where the women serve food in revealing clothing. If you must eat out go to places that only have male waiters and no homosexuals.
Play family oriented sports like tossing a ball around, badminton or volleyball. Make certain your women are properly covered if you play in public. I do not recommend tennis because tennis clothing is too revealing on women.
I also recommend heavy lifting and hobbies like carpentry or stonework to keep yourself busy. Jesus was a carpenter and made his living honestly and kept in good shape doing so.
Encourage your women to learn how to cook healthy food and your boys to learn carpentry and wood carving.