Hey, everyone!
The topic of the day is quite relevant for me, as I'm actively trying to drop some 35 pounds. So far, I'm about 25% of the way there. I'm a bit of a data hound, so I did my research on what would work, and I think the single most important success factor is personalization.
I don't have the patience to track my food intake on an ongoing basis, but I don't mind eating the same thing each day. I have a digital scale, so I can monitor every fluctuation.
The Elan diet plan (3 weeks, 8 pounds and counting):
1) Daily morning weighings & weight tracking. No excuses, no delusions.
2) Zero junk food at or after work. Period. No more buying chips & soda from the vending machines
3) Breakfast: Corn flakes, lowfat milk, banana. A second fruit if still hungry
4) Lunch: big bowl of salad (romaine, cukes, peppers). Sometimes add some sliced egg, tuna, or chickpeas
5) Dinner: try to eat salad first, then have whatever the family's eating.
6) Drinks: Water or seltzer. No soda, no iced tea
From what I've seen, diets fail in the long run because people don't choose plans that they can sustain long-term, and they don't include enough regular feedback & motivation. I think I can eat & live this way more-or-less permanently, I've made sure that my colleagues and family know what I'm doing, and I have a coach who calls me periodically to give encouragement & advice. There was a very nice TED talk a while back on the importance of setting up an external structure (coaching, environment, tools, peers, and data) when trying to effect significant lifestyle changes. Often, failure comes not because of a lack of willpower or desire, but because willpower isn't enough to overcome structural disadvantages.