Consumers who take the time to read the nutrient information on food labels weigh less than those who don’t. In fact, on average there is more than a 9lb (~4kg) difference between those who bother to read the labels and those who choose to ignore them.
In general, men (and particularly smokers) pay less attention to nutrient information when buying groceries. Reading the labels on food packaging is vital to improving diet quality and maintaining a healthy, balanced diet. It allows us to make informed meal and snack choices which provide us with an adequate energy intake (adjustable for weight gain/weight loss/body composition changes) from the correct balance of macro and micronutrients.
Loureiro ML, Yen ST, Nayga RM, The Effects of Nutritional Labels on Obesity, Agricultural Economics, 2012, 43(3): 333.