best weight loss tips for bf?

So my bf have been all talk and no action on his goal to lose weight. I keep telling him just make a small change like not eating too late and more water. He loves food and to drink and hates working out. Has anyone's husband or bf who has lost over 20 pounds tell me their secrets? My bf is upset how he looks and I don't mind how he looks it's just he's very out of shape(out of breath walking) and I don't want him to have health issues going forward. We are 20 so don't have too much stress and bows a good time to get in shape for summer.