You can lose 25 lbs in 40 days on the “No ABCDE” diet: no Alcohol, no Breakfast, no Carbs, no Deviations, and no Exercise.
The main bad carbs are the “white” carbs (flour, rice, pasta, bread, crackers, cereal, sugar).
An easy way to keep to this diet is to eat salads with low-sugar dressings plus vegetables and low-carb add-ons, while alternating between pure veggie salads and salads with chicken or fish.
For example, when I used this diet, my lunch was a veggie patty salad from Subway with guacamole, tomatoes, onions, spinach, jalapenos, cheese, pepper, and olive oil. And for dinner, a similar salad but with chicken plus regular blue cheese or ranch dressing (not low-fat dressing, which has a lot of sugar).
Once I reached my goal weight, I became less strict on the diet, but did the following to maintain my weight: I weighed myself every morning. If I was at or below my goal weight, I let myself eat whatever I wanted for one meal that day. If I was above my goal weight, I went back to strict adherence to the diet until I was at or below my goal weight.
One Idea 