Listen to your mum - dieting is faddish. Instead, improve the "quite" to "all" healthy and eat only nutritionally balanced, healthy foods. Cut out all sweets and junk foods, apart from an occasional treat, as humans would have always done till recent times. The exercise is important, and include plenty of stealth exercise, such as taking the stairs instead of the elevator and cycling to the shops instead of driving, etc.
I used to be 100 pounds heavier than I am now. My eating habits were out of control and pretty much the epitome of mindless. I am A.D.D., I have two kids under four, and I work full time, so eating without constant distractions just doesn't happen. But over the years I’ve learned what it takes for me to lose my weight... and most importantly, keep it off.