Have to agree with this. One of the biggest difficulties is becoming educated on what (enjoyable) foods you can still eat are. My wife chose to lose 30 lbs prior to having kids, and found a free app that enabled her to know her daily intake just by tracking content and serving sizes and setting goals - it was essentially a free competitor to the Weight Watchers app. The app had a large online database of specific food products along with their exact serving sizes, the only additional thing she needed was a food weight scale (~$30). Everything had a point scale and you were allotted X points per day, with an additional Y points per week if you choose to go out during the week.
It was frankly amazing to us how much caloric content is in very small amounts of food. One week my wife had done well and still had weekly points, so we decide to get a slice of Pizza Pizza. Of course the pizza slice had a high point cost, but the shocker was that a single serving of the garlic dipping sauce was almost as many points as the slice itself.
Overall, it worked out for my wife mainly because she enjoyed a variety of raw vegetables and fruits with low calories. Finding low calorie food that you enjoy is probably a significant hurdle for many. It also requires support from those you live with - I personally have a great metabolism and have a terribly high caloric intake which caused many temptations for my wife until I made concessions.