Surplus sugar may cause our cellular powerplants to become less efficient, finds study The average American eats roughly 22 teaspoons of added sugar a day -; more than three times the recommended amount for women and more than double the recommended amount for men. Although this overconsumption is known to contribute to Type 2 diabetes and other disorders, the exact ways in which eating too much sugar sets the stage for metabolic diseases on a cellular level has been less clear. Now, a team led by Van Andel Institute scientists has found that surplus sugar may cause our cellular powerplants -; called mitochondria-; to become less efficient, reducing their energy ouput.