Speaking as a guy here, yes he needs to do it himself. I would also recommend he go some form of low carb. I am doing a modified South Beach Diet. Atkins is also good. I have also heard good things about Weight Watchers Core. I am currently doing a combination of all three although focusing on SBD. All three of these plan allow you to eat until you are satisfied, not stuffed, so you don't have the constant huner to deal with. I would start out on either SBD or Atkins for the first two weeks. Cleansing you body of the bad carbs for two weeks really helps with the cravings later on. A brief definition of each at least in my mind would be.
Atkins: Low Carb, Don't worry about fat. (If you burn it it won't clog your arteries). Extremely restrictive Induction then slowly adds back carbs until weight loss slows.
South Beach: Good Carb, Good Fat. Cuts out the refined carbs. Unlimited vegetables are allowed. Fruits and whole grains are OK starting in phase 2. You limit the saturated fats and transfats. .
WW Core: Lower fat than SBD or Atkins, allows more carbs. Does not have an Induction phase. Has flex points for treats.
Weight Watchers Core may be the best for him longterm. It allows for treats but you have to "pay" for them with flex points. I would start out though on one of the other plans. The weight loss is great in most people those two weeks of induction or phase 1. In the first month, I lost close to 30lbs. Now since then, it has dropped to the between 5 and 10 lb a month. But that first month really gave me a shot in the arm. I was in stage 1 for three weeks before starting to move to stage 2. The first week, I cheated a couple of times so I decided to extend it a week. Since switching to a low carb diet, my blood pressure has dropped from borderline high to normal. I eat peanuts. They are healthy snack foods but I buy the lightly salted. I can't stand unsalted to eat and now regular one taste too salty. Hope some of this helps.