you must be at least eighteen -lrb- 18 -rrb- years of age to use myfitnesspal , eighteen -lrb- 18 -rrb- years of age to use under armour shopping -lrb- unless otherwise specified in separate policies applicable to certain specific jurisdictions -rrb- and at least thirteen -lrb- 13 -rrb- years of age to use the other services .