Question: Emily how can you tell that junk food has influenced your behavior?

Emily Mattacola answered on 19 Nov 2019:

I don’t think there’s much evidence that junk food influences your behaviour, so much as the behaviour of eating junk food being a problem for your health. There’s lot of moral panic around things like eating too much sugar makes kids act hyperactive, for example, but there’s really not much evidence for this at all. Instead, we worry about the cumulative impact of eating too much junk food. We don’t demonise junk food by any means – treating yourself on occasion to a McDonald’s or something similar is not going to affect your health. When eating junk food becomes a regular habit, however, we know that this will have a significant negative impact on your health over time. Junk food is calorie dense but nutrient poor, meaning that we don’t get much good nutrition from it, so it doesn’t keep us full for very long or fulfil our bodies’ needs, but it is very high in calories. This means that, despite potentially consuming half our daily calories in one meal, we could still be really hungry not long after eating it, so we’ll go and eat more. It doesn’t then take much to have eaten more calories than we’ll lose through physical activity, and so your body will turn this excess energy into fat. Junk food also tends to be high in things that can affect how our organs work, things like caffeine, salt and cholesterol, which will have long term impact on our bodies if consumed in excess and might directly contribute towards developing conditions like high blood pressure or having a heart attack.