Low carb, high protein or the other way around? Science shows it doesn't matter what diet you follow, as long as you eat fewer calories than you burn.
A whole armada of scientists looked at how successful diets with different ratios of fat, carbohydrates and protein were.
Most studies in this field never go beyond six months, some keep track of changes for a year. Only very few will monitor their subjects for longer than that. This one now went over two years.
Turns out it doesn't matter what diet you follow, as long as you as you eat fewer calories than you need to maintain your weight:
Reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize.
We did not confirm previous findings that low-carbohydrate or high-protein diets caused increased weight loss at 6 months and that the advantage of these diets usually eroded by 12 months, with weight loss that was nearly or fully equivalent to that with low-fat diets or other diets. Other studies showed increased weight loss at 1 to 2 years with diets that were high in unsaturated fat or with low-fat, high-carbohydrate vegetarian diets. These divergent results suggest that any type of diet, when taught for the purpose of weight loss with enthusiasm and persistence, can be effective.
There you have it: Follow the diet that best suits you. If you think vegetarian is the way to go, so be it. And if you want to take that a step further and think vegan is what best suits your lifestyle, that's what you should do. You could even lose weight with products at fast food restaurants, if you manage to keep the calories in check.
My Frustration Before I (Finally) Lost Weight
I went from 196 to 163 lbs and to do that the composition of my foods had to be of much less concern to me than the calories I wrote down for them. I had tried a diet before and did what what many experted tell you to do: eat vegetables and fruits. This resulted in a disaster.
After five days of having a salad every evening, the sixth day resulted in me eating the salad and throwing up afterwards, because it made me so sick. Eating salad was the healthy thing to do, but how much good did it do for me? I couldn't keep it up, it made me unhappy and frustration set in. Not to mention I then gorged myself in the foods I had deprived myself of.
The Evil Diet
So I designed the "The Evil Diet": I swapped some of the foods I normally eat for their low-cal alternatives; I adjusted my daily eating frequency so that I wouldn't go over my daily calorie limit, but still wouldn't feel hungry; I had the foods I love in smaller quantities and on some days saved calories, so that in the evenings I could have a real portion of one of my preferred foods.
In practice this meant that regular butter, soft drinks and whole milk I replaced with their low cal variants - which was a smaller sacrifice than giving these up entirely - and being able to have the occasional cheeseburger or even a nice tuna pizza in the evening, if I cut back a bit during the day. And those two are foods you are supposed to avoid when you want to lose weight.
Design Your Diet
The only diet you will be able to follow through is the one that suits your individual needs.
If you can find one that fits your bill in a health magazine or book, then great. But if those don't work for you, then it is not your fault. You are an individual and your individual needs might simply differ. Just remember that it is not what you eat, it is always how much you eat, and as long as your nutrition doesn't lead you to develop deficiencies, you will be healthy and will lose weight.