The effects of non-nutritive sweetened (NNS) beverages on weight management and psychological indices of appetitive behaviour have not been assessed in both weight loss and maintained weight loss phases over the long term to determine whether NNS beverages may assist in efforts to lose weight and maintain weight loss and how this affects appetite expression (satiety, food choice, craving, ease of dieting etc.). Thus the present research will determine the impact of NNS beverages as compared to water on weight loss and weight loss maintenance, satiation, satiety, cravings for sweet, exercise efforts and mood state across both a period of weight-loss as well as a weight-maintenance phase. To determine if the effects of NNS on appetite are beneficial or detrimental to successful weight management, the study will also systematically compare the effects of NNS beverages, water and caloric beverages (CBs) on appetite (hunger, satiety, liking and wanting) and energy intake (including food choice and caloric compensation) across the whole day during active weight management in a subset of participants.