I stumbled onto something magical a few years ago. Magical for me anyway but it is pretty much becoming standard thought in eating and 'dieting.' It changed everything for me. I was 42 and thinking I'd never again be in shape, lose the belly and have energy like I did in my 20's. I have more energy now and am in better shape.
I'd tell my own story but it would sound worse than a bad infomercial. The end result though is that I am in better shape in my 40s than 20s, have more energy and feel better.
Don't think of it as dieting first of all, it has to be a permanent change in the way you eat. Don't 'try' to lose weight, that sucks. Dieting sucks, counting calories and making food a reward game sucks. Try to focus on and change destructive eating habits and let the weight loss be a nice consequence.
The cool part is that you really don't have to restrict your diet to do it right. I ate considerably more and still do.
First of all, eat 6 meals a day, 3 'normal' with 3 protein shakes in between but don't go longer than 3 hours without eating. Have your biggest meal in the morning, lightest at night. This keeps your metabolism burning. When your stomach is empty your body starts preserving energy and calories, you don't want that.
Next, be SURE to do a little exercise in the morning to get the metabolism going. Not necessarily cardio, just some basic push ups and maybe simple calisthenics. 5-10 minutes tops. You can do more at the gym later if you like but do this in the morning. A stretch band for your stomach and core is good too, you want your muscles burning your calories for you during the day. Fire them up in the morning and they will. Do just enough to feel good and get your heart going and muscles building, I started out with about 20 pushups and slowly added more to get to that 'feel good' zone. It isn't about 'No Pain No Gain,' just do enough of something to feel 'good.' You just want to have a nice glow. It will take more and more exercise to get there.
Finally, what to eat. First get rid of white foods. Starches, breads, most pasta, grains, sugars, white rice. They not only pack a whallop in calories, they wear you down and make you lethargic. A double whammy. These foods concentrate huge calories into small portions. You can eat a lot more overall by simply avoiding them.
A meal is just one fist sized portion of proteins, one of carbs, and as many vegetables as you want to eat. Stick with good fat sources and avoid fried fats. Simple and easy. You should never have to feel hungry or depleted of energy, in fact you should feel the opposite in a 'diet.'
I got a Vitamix later and stepped it up even more but that isn't necessary. Protein shakes in between are fine.
Good fats (basic list):
cold water fish
olive oil, sunflower oil, canola oil, flax seed oil
Food to avoid:
whole dairy anything
Some good proteins:
lean ground beef
baked potato (I limit them myself)
whole wheat pasta (I still avoid it mostly)
high fiber cereal
There is is in basic form. Eat often, eat right, don't worry or focus on weight. Focus on your metabolism and feeling good. After not very long the foods you used to crave will seem disgustingly rich, weight will drop off like melted butter, you will look and feel great. I promise...