You could try putting his food in a certain place and yours in another. Then, you avoid the junk food area the way I avoid the alcohol aisle at the grocery store and are never even strongly tempted.
I work in a HOSPITAL full of OBESE NURSES. I take comfort in turning down offers of donuts and cookies, and usually take the window to toss in " Healthy, saturated animal fat is good for us, sugar and grains are not" just to get their wheels turning. It's a place where health should be sought, and instead these so-called professional people blatantly shun it. I've always taken sadistic pride in going against the grain, so when it's such a fun and righteous splash, I can't resist. And, yes, when the little brown spongy circles of death meet my eyes, the first thoughts that come to me are the hot flash, the instant boils that will appear on my face, and the water weight I'll carry for days. And I'm a guy. I can't imagine the battle women face around their fat friends constantly trying to drag them down into the gluttony.
Steak, eggs, potatoes - fruits, nuts, berries and forage. Coconut milk and potent herbs and spices. Tea instead of coffee now and teeny amounts of kelp daily. Let's see how this does! Not really had dairy much, and gut seems better for it.