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.
All meals are important, but breakfast is what helps you start your day on the right track. The best, heartiest breakfasts are ones that will fill you up, keep you satisfied, and stave off cravings later in the day. Aim to eat anywhere between 400 and 500 calories for your morning meal, and make sure you're including a source of lean protein plus filling fat (e.g., eggs, beans, unsweetened Greek yogurt, nuts, or nut butters) and fiber (veggies, fruit, or 100% whole grains). Starting your day with a blood sugar-stabilizing blend of nutrients will help you slim down without sacrifice.
Have you been consistent with workouts but haven’t gotten the results you were hoping for? Your low-key resolution is to change up your workout. Commit to the same number of workouts per week, but make these workouts completely different. If you’ve been going to yoga three times a week, go to a cycling class instead. Or if you’re walking on the treadmill every day, move over to the recumbent bike instead. By sparking a change in your routine, your muscles will be forced to work differently and hopefully you’ll begin to see the results you’ve been hoping for!