According to the research published in the 'Experimental and Clinical Psychopharmacology', habitual coffee drinkers are not just more sensitive to the odour of coffee and faster to identify it, but the more they crave for coffee, the better their ability to smell becomes.
Rachael and Richard Heller have conducted extensive research into the carbohydrate-insulin connection and discovered that excess amount of insulin in our blood cause us to store more fat and crave for starches and sweets.