The invention discloses synergistic herbal composition comprising combination of first ingredient selected from extracts, fractions, phytochemicals and mixtures thereof derived from Theobroma cacao and a second ingredient selected from extracts, fractions, phytochemical and mixtures thereof derived from Citrus aurantifolia for obtaining at least one health benefit selected from preventing, controlling or treating obesity and/or overweight; improving lean body mass, improving the browning of White Adipose Tissue/improving formation of brown adipose tissue, increasing basal metabolic rate/resting energy expenditure, increasing thermogenesis, improving thyroid function, maintaining healthy body weight, increasing satiety/, supporting weight loss, improving fat loss and maintaining a slim body. The invention further discloses synergistic herbal compositions comprising Theobroma cacao and Citrus aurantifolia and optionally comprises at least one ingredient selected from pharmaceutically acceptable excipient/diluent/carrier; methods of treatment and use for the prevention and treatment of obesity/overweight or improving lean body mass or resting energy expenditure in a human or animal.