The problem is every body knows that broccoli is healthier than a piece of cake, but we want the cake, and we eat the cake instead of the broccoli.
So unless we come to terms with this and really learn to make healthier choices, eating healthy is not going to happen no matter what we want and know we should do.

For many folks, it's a lot more complicated than cake (that is desire for unhealthy foods).

If giving up cake, and junk food and eating only "healthy foods" were the solution, I would have lost all the weight I needed to, maybe fifteen years ago.

The problem is, a healthy diet is more than just quality - it's quantity as well (and can't be separated from other healthy choices in your life, either such as activity level, stress, sleep quality/quantity - it's a package deal).

And of course, overeating fresh cherries, lychee fruit, whole grain cereal, starchy vegetables, avocado.... is still overeating.

I went to a consultation for a weight loss program in our area a couple years ago (It was a great program, and I would have signed up in a minute, if we'd been able to afford it, but insurances and Medicare don't cover it - they'll cover wls, but not a diet and exercise program).

Part of the evaluation process was a diet survey, and the nutritionist asked if I'd ever had my thyroid tested, because my diet looked remarkably healthy for a person of my size. I told her that my thyroid had been tested, and the hormone leves were found to be low but close enough to normal that my doctor didn't want to prescribe synthroid. I pointed out that I wasn't very active because of my health problems, and that the survey hadn't really asked about portions. I did eat more than 5 servings of fruits and vegetables, and I did eat more lean meats than fatty meats, I was (at the time) eating quite a few servings of whole grains and starchy vegetables (which I didn't count in the 5 servings of fruits and vegetables, because I consider them "bread" or carbohydrate servings, not fruits and vegetables), but the fact was I was obviously eating more than I needed (even though it was a fraction of what I was eating when I was younger and gained most of the weight - the healthy diet was keeping me from gaining weight, but wasn't sufficient to help me lose the weight because of the huge drop in my activity level).

The dietitian and doctor heading the program agreed that for me, it was an issue of quantity, not quality (and recommended a low carb and/or low GI diet).

That's been working very well for me, when I stick to it - I still can't shake decades and decades of indoctrination that low-carb diets are unhealthy and even dangerous. Even though I've proven it to myself, I still have a hard time accepting low-carb eating as "healthy."

But that's my problelm, and it has no bearing on the truth. The truth is that for me, starchy and sugary foods - even the healthiest of them, are not healthy for me.

Diet plans are sold by rhetoric-- the art of convincing people. I do not believe that only one thing will cause an overweight person to lose weight. It will be a combination of a lot of things. Ommitting "junk" from the diet, lowering calories, lowering food volume, raising the amount of exersise the person does, and managing stress so over-eating will not happen. People have different styles of accepting information. Some like the packaged plans because they see something great about packages, and they believe they need that sort of assistance. Some like the "eat only one sort of thing" type regime, because they listen to, and believe the experts. Some decide to count calories, and some decide to go vegan. There are a lot of ways to go, and a lot of ways to do it. I'm a low/carb paleo type dieter. I also believe in one meal a day, and forgoing eating until I am very hungry. Others might like totally man-made medicine tasting stuff. Lesson learned: Dieting is 99% mental. Once you get to the place where you know you are in control of what you feed the beast, you don't let it beat you up any more. Let it whine, let it cry, it will not get the potato chips back, or the candy-- you are in control. Whatever that means.

I've wondered the same thing.
I've tried several diets in the past but this time I am just doing the same thing you are. To me, there is too much stress involved in trying to follow some really specific diet that makes me feel bad when I can't do exactly what I'm supposed at every meal.
So I am just counting calories...staying below 1200 calories a day. I quit eating sweets. I started drinking water instead of soda. And I am exercising.
I've only been at it a week but I am still learning what I am capable of...which is a lot more than I thought.