Roberts argued that weight is controlled by maintaining body fat at a certain amount, referred to as a "set point." When weight is above the set point, appetite decreases, and it takes less food to feel full. When weight is below the set point, appetite increases, and it takes more food to feel full. He further stated that eating strongly flavored foods (like soda or donuts) can raise the set point, whereas flavorless foods (like sugar water, canola oil, extra light olive oil) can lower the set point. These flavorless foods must be consumed in a "flavorless window," at least one hour after and one hour before consuming flavors. Consumption of 100-400 flavorless calories per day lowers the set point, and therefore, lowers weight.