You ARE the Gatekeeper!
I know it may sound sexist, but if you, Mom, are the one who does the shopping, then you are the gatekeeper to your family's health. It's mostly in your hands whether your family IS or becomes overweight. And what your children see you do makes you as parents the gateway. If you as a mother are overweight, the foods you choose for your family could very well be helping your children become over weight. If your children see their parents eating cleanly and exercising they will also adapt to that lifestyle.