There is a simple universal truth to losing weight, you have to burn more calories than you consume. The industry has over complicated this simple universal truth by having programs with numerous dietary restrictions and strict menu plans. So in order to keep your focus on this simple universal truth, invest a few hours over a week or two learning about the calorie values for foods you typically eat. MyFitnessPal has a great free app and the NIH has a recommendation on how many calories you should be consuming per day http://www.nhlbi.nih.gov/health/educational/wecan/healthy-weight-basics/balance.htm
For me personally, I invested a few hours over a two week period of time to learn about the calorie values of foods that I commonly eat. This involved me simply reading a label for items that were in my house and leveraging a free calorie app on my iPhone. After the initial investment into learning calories, portion control comes naturally.
For those of you associating that learning calories takes too much time, I would encourage you to think about some other diets you have tried. Think about the time required to go to the grocery store including buying items that are not in your home, the time to prepare meals to follow an exact meal plan, etc. Investing a few hours over a two week period of time is far less time than it is to follow standard diets and is far more beneficial for long term success.
I can’t tell you how many diets I have failed at by implementing drastic calorie reductions and radically changing food choices in a single day. It took me over 15 years of failing to realize you can’t correct decades of poor eating habits in a single day. Take it slow with making changes to calorie reductions and incorporating more healthy food over time and you will succeed long term.