1.Baked/broiled fish tacos.
Whole wheat tortillas, natch.
Go easy on the fat you use to prepare the fish and when pulled from pan drain and blot the fat off, I promise you it will still taste great.
2. Teach portion control and how to read the nutrition labels.
3. Take them on a shopping expedition and show your clients the good subs for those yummy, fatty things in the boxes and bags (and how to prepare them)
4. Stir fry with lots of flavorful (and colorful) veg and prove to them that you don't have to have a lot of protein to make the fry satisfying.
5. Desserts are allowed, try "braising" apples in apple juice then adding some apple pie spices.
If faced with a dessert buffet, just take one or two bites of what they cannot live without, or better yet get extra spoons so you can share!
Everything in moderation.
Let them know that butter is not the enemy, just buy the best, most flavorful product they can afford and just use less.
Same with salt, it is a myth that salt will cause hypertension, however those that already have this condition,too much will cause retention of fluid and may make it worse.
To not buy all the products (that fake butter spray comes to mind) that promise low fat/no fat .
These products most likely contain lots of sugar so they "taste better".
Again, read the labels!