"Mottainai" means "what a waste" in Japanese and was introduced by Wangari Maathai, 2004 Nobel Peace Prize winner, in an United Nations conference. A very cute children's book called "Mottainai Grandma" is now available from Kodansha Publishing.
My grandmother, who grew up poor in China, has her own version of "mottainai". As a kid, she would save the baking tins used for pies as plates and have us drink out of empty glass jars. We couldn't throw anything out nor could we leave any bit of food on our plates.