Small children restrict their food intake for many reasons: to ignore this is to take too simplistic a view.
Children stop eating, for example, when they are acutely distressed, if they are in an abusive relationship or have serious health problems.
University research, however, shows that girls as young as five have internalised the "thin ideal".
In one experiment, children were shown the same five-year-old girl, wearing a swimming costume, increasing in size. Most found that the least desirable child was the most overweight.
In another experiment, they took a child's doll with exaggerated thinness, length of leg and size of breasts and asked girls to play either with that or a doll modelled on an average woman's body. The five-year-olds rejected the latter.
There are insidious cultural influences that are highlighted by such research and by younger children complaining that they have a fat tummy or thighs. They are looking at their bodies in a critical way because of the images that make up the wallpaper of their lives.
But the reasons very young children self-starve are complex and cannot just be explained by social pressures.
To self-starve you need a certain level of critical thinking, self-hatred and low self-esteem. By five, most children have a pre-frontal cortex (that allows us to match ourselves against social norms) that's up and running. But critical evaluation comes from experience and most five-year-olds have not lived long enough to amass such experience.
There are other types of eating disorders affecting children. There are more morbidly obese five-year-olds than severely underweight ones. Why aren't we questioning this? While we are horrified by the very thin child, we seem more accepting of a child who is overweight.
Overweight children not only have greater long-term health risks but also psychological, emotional and often social problems when they are older.
I have huge concerns for children whose parents neglect their health and well-being by not feeding them properly and allowing them to become overweight.
They are feeding them up towards potentially major problems and we must confront this.