A composition for inhibiting ketohexokinase, for example, ketohexokinase-C (KHK-C) activity, may include a plant extract exhibiting at least IC50 (i.e., 50% KHK-C inhibition at a concentration in the range of from about 0.1 &mug/mL to about 1000 &mug/mL. The composition may be in a form suitable for oral ingestion. A method for inhibiting KHK-C activity in a subject may include administering a plant extract that exhibits at least 50% KHK-C inhibition at a concentration from about 0.1 &mug/mL to about 1000 &mug/mL. The administering may be done to treat or prevent at least one of sugar addiction, obesity, or metabolic syndrome. The administering may be done to provide a diminished craving in the subject from at least one member selected from the group consisting of craving of sugar, fructose, fructose-containing sugars, carbohydrates, and combinations thereof. The subject may be pre-diabetic, diabetic and or insulin resistant.
