Cooking your own meals is, of course, optimal, and folks who have the time and energy to do so should do so as much as possible. Typically, folks choose meal replacement entrees because they don't have the time or energy, and need the convenience. Choosing based on protein content, as Susan alludes to, is a very good idea. I try to evaluate all food choices based on protein grams per calorie. Some Lean Cuisines and such are good with respect to protein -- others aren't. Always read labels! However, for folks trying to lose weight, or keep it off, meal replacements are almost always healthier choices than high-fat or high-calorie alternatives.