Losing weight can be as simple as 1, 2, 3.
1. Don't eat anything with SUGAR in it.
2. Don't eat anything with FLOUR in it.
3. Exercise hard (aerobic), 3-4 times a week for 15-20 minutes.
In the Crossfit classes I go to, I've seen simply AMAZING results from folks, young and old, that follow this simple regimen.
The science behind this is sound. Just google "paleo diet" and "zone diet" for the facts, but you really don't have to go to the extremes those "diets" promulgate. You don't have to worry about portions, or food balancing/ratios etc. If you do TKD, I know you have the discipline to follow the simple plan above. Eat as much as you like. Just watch VERY CAREFULLY that what you are eating has no sugar or glutens. Simple fresh meals are easier to monitor than processed foods. Fresh meat and vegies. As much as you want!
For faster results, go VERY easy on the starches (potatoes, rice) and legumes (beans). Some folks I know dropped an incredible amount of weight very quickly by cutting out the starches and legumes along with the sugar and flour products. But that can be more difficult to do for some people, and they get discouraged.
READ THE LABELS of everything you add to your food, like condiments. If there is ANY sugar or gluten in them, find a substitute. If you're like me and just HAVE to have sweetener in your coffee, replace sugar with Stevia.
And, if you are following these guidelines religiously, give yourself a treat. Let yourself cheat one day a week and eat anything you like. That way it's easier to be social, or hang out with the family and friends without totally stressing yourself (or them), or coming off like a total freak in public. Chances are you'll feel so good after a couple of weeks of this, that you won't want to cheat, but .... it's OK.
Just like the Sly challenge ... Give it a shot for 30 days!