How many athletes playing in Canoeing fall into overweight BMI category in the 2008 Summer games?
fall into overweight BMI category refers to DIVIDE(weight), MULTIPLY(height, height) < 30; Canoeing refers to a sport name; the 2008 Summer games refer to games_name = '2008 Summer';
SELECT COUNT(T5.id) FROM sport AS T1 INNER JOIN event AS T2 ON T1.id = T2.sport_id INNER JOIN competitor_event AS T3 ON T2.id = T3.event_id INNER JOIN games_competitor AS T4 ON T3.competitor_id = T4.id INNER JOIN person AS T5 ON T4.person_id = T5.id INNER JOIN games AS T6 ON T4.games_id = T6.id WHERE T1.sport_name = 'Canoeing' AND T6.games_name = '2008 Summer' AND T5.weight * 10000.0 / (T5.height * T5.height) BETWEEN 25.0 AND 30