While the Duke study found no added benefit to resistance training (aka weight or strength training) when it comes to belly fat, a 2014 study from a Harvard University team found otherwise. Twenty minutes of weights a day was linked to less of an increase in belly fat (particularly for older men). “Engaging in resistance training or, ideally, combining it with aerobic exercise could help older adults lessen abdominal fat while increasing or preserving muscle mass," said the paper’s lead author Rania Mekary.
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.
At its core, burning fat comes down to the process of lipolysis—the breaking down of fat lipids, explains Seedman. This happens in the mitochondria of the muscles, or the powerhouses of the cells, responsible for generating the energy our cells need to do their jobs. Exercise has been shown to improve mitochondria function, which then promotes fat breakdown, Seedman adds. Plus, working out helps regulate pretty much all the hormones that optimize fat loss.