Here's an interesting thought to keep in mind. If all you do is fast just one day a week, it adds up spectacularly. In seven years, you will have fasted for one entire year. For the average person, that represents 1.5 pounds saved every two weeks—39 lbs in body weight at the end of the seven years! What do you think a year of fasting every seven years would do to optimize your health—let alone slow down any weight gain you might otherwise have experienced?
You can acquire CLA from supplements as opposed to natural foods, but it might not be as beneficial, considering CLA found in supplements is not the most effective type for stopping fat storage. Whole foods are made of CLA isomers called c9, t11, while many supplements are high in the types of CLA called t10, c12, which have less drastic effects. Your best bet is to eat foods that supply relatively high doses: real butter from grass-fed cows (ideally organic), full-fat dairy (preferably raw and possibly fermented, such as yogurt), grass-fed beef, and to a lesser degree grass-fed lamb, veal, turkey and wild-caught seafood.
Dinner? That's miso soup with some chopped sea vegetables (like the Japanese nori, used to make sushi) snipped over top. Or you might choose a cup of brown rice with a few chopped vegetables mixed in. "Brown rice gives your body plenty of B vitamins, which is a stress reducer. It's very high fiber, will fill you up, will help you sleep, and will flush you out in the morning."