Ages 10–17 · Kid Mode and Teen Mode

Children are affected too.
They are not small adults.

Inactivity and its consequences reach children as much as adults, so the engine serves both. What changes is everything a child actually sees. The assessment exists for safety and escalation. The target does not exist at all.

The line we do not cross

Assessed for safety. Never handed a number.

A clinician may need an age- and sex-adjusted centile to spot a child who needs help. A ten-year-old does not need to see it, and showing it does harm. Those two facts are not in tension — they just require the product to keep them apart.

A child never sees

A weight, a BMI number or a calorie figure — shown to a child, in any mode, under any consent
A body-composition target, however gently worded
A leaderboard, ranking or comparison against another named child
Streak-loss messaging, countdowns or punishment for a missed day
Weight-loss contests, fasting challenges or calorie-minimisation games
Open discovery, adult contact, or a public profile

A child always gets

Growth, energy, confidence, food variety, family routines, activity and sleep
A guardian account, with the child as a linked profile — never standalone
Crews that are class-based or family-based, created by a verified adult
Play framing: "Beat the Kettle", "Floor is Lava 90", the Rainbow Mission
Escalation to a professional when the assessment warrants it, not a target
High-privacy defaults under the Age Appropriate Design Code

Enforced, not promised

The consent switch does nothing under 18.

Most products make this a setting a parent can turn on. Here it is not a setting. A request for a reduction pathway from an eleven-year-old — with body metrics explicitly opted in — comes back as growth, with metrics withheld.

POST /api/body/assessrequest

{
  "age": 11,
  "requestedPathway": "REDUCE",
  "optedIntoBodyMetrics": true,
  "heightCm": 145,
  "weightKg": 48
}

200 OKresponse

{
  "pathway": "CHILD_GROWTH",
  "metrics": null,
  "safety": {
    "reductionPermitted": false,
    "powersExercised": [
      "activate_child_safe_mode",
      "block_weight_loss_plan"
    ]
  }
}

// the opt-in was ignored, by design

A day in Kid Mode

Six actions. None of them about a body.

The anchor is the one that happens even on a difficult day. Everything else is optional in practice, and the last one is optional by label.

Anchor

Do the two-minute Wake-Up Shake before school.It is short, and it is the one that matters most today.

82%

Food

Add one new colour to your plate at dinner.More colours means more of the good stuff. No counting, no measuring.

74%

Movement

Beat the Kettle — move until it boils.A game, not a workout.

79%

Strength

Try five Superhero Holds.Building strong is about what your body can do.

68%

Recovery

Screens down fifteen minutes before bed.Sleep is when your body does the growing.

61%

Optional

Show a grown-up one move you learned.Teaching it makes it stick. Skipping it costs nothing.

55%

The two child modes

Ten to twelve is not thirteen to seventeen.

Explorer Mode · 10–12

Play-framed, permission-giving, safe. Never evaluative about the body.

Guardian account required; no standalone profile
3 nudges a day, hard ceiling
No free-text with the AI — structured prompts only
No biometrics, no precise location, no ambient sensing
Reading age 9 · WCAG AAA

Teen Mode · 13–17

Dry, low-hype, zero kiddie language, zero body-image framing.

Self-registration with age assurance
Guardian visibility is configurable and disclosed to the teen — never covert
4 nudges a day
Crews inside a school tenancy or invite-only graph
Exam-season Focus Snaps; no body-image framing, ever

Every body qualifies. Including the small ones.

A parent or guardian creates the account and confirms it before anything opens. No weight, no calories, no body talk — enforced by a test, not a policy. Schools and clubs are a different route.

Create a family account For schools and clubs

Free to create. 150 AI credits a month for 2 months, then AI features need a plan — everything that is not AI carries on either way. Premium is £5.99 a month and cancels in one click. Under 18 a guardian confirms before the account opens.

Children are affected too.They are not small adults.