BACKGROUND: Glycemic index has generated a lot of debate for nearly 30 years, especially as it relates to the control for the treatment of diabetes. OBJECTIVES: This study determined the glycemic index (GI) of ten processed Nigerian foods and revealed their similarity in the release of glucose on consumption. METHODS: The food items tested were made from yam tubers, cassava tubers and local cereals. These foods were served to human volunteers in several processed forms which resulted in viscous pastes. RESULTS: The GI results are related to the increased incidence of overweight and obesity in the middle class Nigerians. CONCLUSION: It is suggested that these processed foods should be discouraged in the regular dietary plan if Nigerians desire to stay slim and save the planet by reducing carbon emission and climate change.