In short

If your daughter says she wants to lose weight, take a breath before reacting. Most teen girls feel this at some point, often pushed by social media or comments at school. 

The healthiest response is to focus on how she feels and what her body can do, not the number on the scale. 

Talk about food, sleep, and movement as ways to feel good, not shrink. Watch for signs that dieting is tipping into restriction, secrecy, or distress, and speak to your GP if it does.

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Why does my teenage daughter want to lose weight?

Almost always, it's external pressure, not something wrong with her body. Teen girls are flooded with edited images, salt water diet trends, and "what I eat in a day" videos, and most have absorbed the idea that thinner means better.

On top of this, many teens compare themselves to everyone online, and when they are faced with influencers with the “perfect” body, their self-esteem can really take a hit.

In a luna poll of 1,464 teen girls, 54% said they edit or filter their appearance in photos before posting online. 

In another luna poll of 2,156 girls, 22% named body image as their top summer worry. The pressure is constant, and it lands hardest in puberty, when bodies are changing fastest.

Common triggers include:

• A comment from a friend, sibling, partner or relative about her body
• Changes in her body during puberty: hips, breasts, weight redistribution
• A TikTok or Instagram trend, such as SkinnyTok
• Starting secondary school or a new year group
• Bullying, even low-level "banter"
• A friendship group where dieting or "clean eating" is the norm

She probably doesn't need to lose weight. She probably needs to feel okay in the body she has.

Should my teenage daughter be losing weight at all?

For most healthy teens, no. Adolescence is a time of rapid growth, and restricting food during puberty can affect height, hormones, periods, and bone density. 

The NHS does not recommend weight loss diets for healthy children and young people.

If a doctor has identified a clinical reason for her to lose weight, they'll guide that, usually with family-wide habit changes rather than calorie counting. Outside of that, the goal is healthy growth, not a smaller body.

A few things worth knowing:

• Bodies shift dramatically between 11 and 18, and often settle into their adult shape in the early twenties
• Weight gain in female puberty is normal and necessary, especially around the hips, thighs, and chest
• Teen girls need more iron, calcium, and energy than at almost any other point in childhood

How should I respond when my daughter brings it up?

Start by listening, not fixing. If she's told you she wants to lose weight or that she thinks she’s fat, that took something. Try not to react with panic, agreement, or "don't be silly".

A calm, curious response works best. Try:

• "What's making you think about that?"
• "Where's that coming from?"
• "How are you feeling about your body lately?"

Let her talk. You're trying to find out what's underneath: a comment, a video, a friendship, a feeling. Often, the wanting to lose weight is the surface, and there's something else behind it.

Then gently steer the conversation toward how she feels, not how she looks. Ask if she's eating enough, sleeping enough, and moving in a way she enjoys. Those are the levers she actually has.

What should I never say to my daughter about her weight?

Some phrases land harder than parents realise. Avoid:

• "You don't need to lose weight, you're beautiful": it still ties her worth to her looks
• "I went through the same thing at your age", followed by a story about your own diet
• "Well, if you cut out X you'd lose a few pounds": don't help her diet
• "You've put on a bit of weight, haven't you", even softly, even once
• Comments about other people's bodies, including your own, in front of her

Research links parental weight talk to higher rates of disordered eating in teens. Teens whose parents commented on their weight, even kindly, were more likely to develop an unhealthy relationship with food.

For more information on how your own behaviour impacts your teen's feelings about dieting and weight loss, check out luna’s article on almond mums. 

How do I help her without focusing on weight?

Shift the language from weight to wellbeing. You're aiming for her to feel strong, energetic, and at home in her body, not smaller.

Things that help:

• Eat together when you can: family meals that focus on healthy eating are one of the strongest protective factors against disordered eating
• Don't label foods "good" or "bad": all foods can fit, and restriction tends to backfire
• Move for joy, not punishment: dance, walks, swimming, climbing, team sport, whatever she actually likes
• Audit her feed together: unfollow accounts that make her feel worse, follow ones that show real bodies, athletes and hobbies
• Talk about what bodies do, not how they look: "your legs got you up that hill" beats "your legs look great"
• Watch your own talk: if you're dieting out loud or moaning about your thighs, she's listening

When should I worry it's becoming an eating disorder?

Wanting to lose weight is common. An eating disorder is different, and it can develop quickly. Trust your gut, and book a GP appointment if you notice:

• Skipping meals, hiding food, or eating in secret
• A sudden cut-out of whole food groups (carbs, fats, anything "unhealthy")
• New rituals around food: cutting tiny pieces, weighing portions, very slow eating
• Excessive exercise, especially solo and rule-bound
• Weight loss, missed periods, dizziness, or feeling cold all the time
• Pulling away from friends or activities she used to enjoy
• Distress around eating, the mirror, or photos of herself
• Preoccupation with calories, ingredients, or her body

Early help makes recovery more likely. 

You don't need to be sure: if something feels off, see your GP and ask about a referral to CAMHS (Child and Adolescent Mental Health Services) or a specialist eating disorder service. 

Beat, the UK's eating disorder charity, also runs a free helpline for parents. 

FAQ

Is it normal for my teenage daughter to want to lose weight?

Sadly, yes. Most teen girls in the UK report dissatisfaction with their bodies at some point, usually pushed by social media and peer comments. 

Common doesn't mean fine, though, and how you respond matters more than you think.

Should I put my teenage daughter on a diet?

No. The NHS doesn't recommend weight loss diets for healthy children and teens. 

Restriction during puberty can affect growth, hormones, and periods, and parent-led dieting is one of the strongest predictors of disordered eating later. 

If you're worried about her health, speak to your GP first.

My daughter is overweight, what should I do?

Speak to your GP before doing anything else. 

If a doctor agrees her weight is affecting her health, they'll guide a plan, usually built around family-wide changes like more home-cooked meals, better sleep, and more movement, rather than singling her out or counting calories.

How do I stop my daughter comparing herself to people on social media?

You probably can't stop the comparison, but you can change what she sees. Sit with her and unfollow accounts that make her feel worse. Add accounts that show real bodies, athletes, and her actual interests. 

Agree a screen-time limit together. And keep talking, because quiet daughters compare more.

What if she gets angry when I bring it up?

That's normal. Don't push. Say "I'm here when you want to talk", and mean it. Keep the door open with low-stakes time together: a walk, a drive, cooking. Most teen girls open up sideways, not face-on.

If your daughter has come to you about her weight, that's a sign she trusts you, even if it doesn't feel like it. 

Listen first, steer toward how she feels rather than how she looks, and if you're worried it's tipping into something more, speak to your GP. Early help works. 

For more ways to help your teen, check out luna’s article on body image tips for parents.

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