Even now, 10 years on, I can still remember the cold, white fear I felt when my daughter Lily, then 8, announced she was putting herself on a diet. A friend had called her "fat" during a playground quarrel, so "no", she announced briskly, she wasn't going to have her usual crumpet for her tea.
First my mind went blank. Then it felt like I was stepping into a minefield. As it turned out, it was to be the first skirmish in a long and challenging battle to keep my two daughters feeling good about their bodies in a culture which is constantly bombarding them with negative messages about how they look.
As a parent, I know I am not alone. So who among us didn't feel a twinge of sympathy this week for the TV presenter Jonathan Ross and his wife Jane after their daughter Honey revealed they tried to suggest diets when she felt unhappy about her weight as a teenager?
On the TV panel show Loose Women, the 23-year-old writer and activist, now a proud advocate of body acceptance, said she "hated her body" from a young age. Honey added that her parents "tried to give me solutions to a problem I brought to them, which was to lose weight. They presented me with diets and diets, as we know, don't work and are absolutely toxic".
Honey is absolutely right that dieting does not solve weight problems; it often creates them, and 95 per cent of them fail. But in a world where health concerns about obesity have never been more feverish – especially now it has been shown to increase the risk of death from Covid-19 by almost 50 per cent – many parents feel at a loss for what to say when faced with the most difficult question a teen will ever ask: "Do I look fat in this?"
And it's something more parents are struggling to find the right words to answer, as it's feared that more children than ever have slipped out of their healthy BMI range, thanks to boredom-snacking and a more sedentary lifestyle during lockdown.
Indeed, as author of the books Girls Uninterrupted and What's my Teenager Thinking?, I would go as far as to say that knowing what to say in these moments has become the single most difficult tight-rope to walk in parenting.
After all, we are raising children in a nation of two extremes. On the one hand, the UK has one of the highest rates of childhood obesity in Europe: around one in five children aged 10 to 11 are classified as such, and seven out of 10 overweight 11-year-olds go on to become obese young adults.
Yet we are almost struck dumb by the crushing responsibility to get the messaging right. If we say the wrong thing – or overdo the healthy eating too much in our own homes – we may be tipping our children toward an eating disorder like anorexia or bulimia.
Social media means they are already growing up in a distorted hall of mirrors, in which they are exposed to more images of "physical perfection" than at any other time in history. Even if your daughter or son isn't on Instagram or Snapchat, their peers will be.
My daughter Clio, now 15, has told me how even at primary school, lunchtimes were turned into contests to see who could eat the least, where girls sat in judgment on each other's plates and lunch boxes. Forgoing desserts and loudly announcing this self-denial to your peers was a badge of honour within a classroom hierarchy where the slenderest girls perch on the top.
But there's also another elephant in the room: and that is that many parents secretly fear that having an overweight child is a reflection on them – making them feel like failures for being neglectful.
So, how should parents broach the subject, especially if they fear there is a genuine cause for concern? First, check your own attitudes. We all live in a body conscious world. Is it possible your child has simply slipped outside of your mental template for how they should look? Remember that children's shapes are constantly shifting as they move towards adulthood and that girls, in particular, can put on 20 per cent of their body fat during puberty – and often put on weight before a growth spurt. So be careful not to jump the gun by fretting unnecessarily.
If your child comes to you with the killer questions: "Am I fat?" or "Have I put on weight?", there is simply no right answer. Every parent's instinct is to rush to deny or reassure, but listen carefully, acknowledge their feelings, and resist the temptation to either agree or disagree.
Above all, avoid the diet trap. Research has also found that young people feel good about their bodies when their parents emphasise the positive ways they can keep a healthy weight, not when they limit or forbid certain foods (they are likely to do the opposite and seek them out, to exert their independence).
At a time when your child is not upset, talk about how it's up to them to make choices that will support their body and make it work most efficiently. Encourage them to work out for themselves when they feel hungry, and to work out when they are eating just because they feel bored or upset.
Beyond that, if your son and daughter genuinely need to lose weight, the best way is for the whole family to work on reducing portions and increasing their exercise, so no one feels singled out. Tell your child that if they want to change how much they eat and exercise, they are not alone and you will work on it together.
As Honey Ross, who has so deftly brought this most difficult struggle for families out in the open, said herself: "I think compassion and kindness are the most incredible gifts to give a child. Even if you do want them to lose weight, when has shaming ever been a motivator?"
How to talk to your child about weight
Don't use the "d" word: Diets are not the answer for children, but healthy lifestyle choices are. Tell them to eat when they are hungry because eating well and regularly is essential to keep their mood balanced and to stop them feeling deprived. Emphasise quality, not quantity of food. And when it comes to exercise, make strength and flexibility the goal – not skinniness.
Acknowledge their feelings: If your child says they have nothing to wear because they are "too fat," let them express their frustration. Say: "You sound worried about choosing an outfit." Uncontradicted, a strong feeling can fade in just 90 seconds.
Talk about different body types: Self-acceptance is a key part of developing a healthy body image. At neutral times, explain that there are different body types laid down in our genes – models just have the DNA that makes them tall and thin – and healthy weight is different for every person, based on build and height.
Listen carefully: Eating disorders are often the last resort for young people who are not being heard any other way, or are trying to rebel. Overscheduled and under pressure to be perfect, they may protest with the one thing they do have control over – food. Make sure your child can really talk to you, and hear what they are saying, not what you want to hear.