How do I get started?

Start with the free TDEE calculator at https://nanorhino.com/tdee — a 5-minute AI interview (no app, no account) that gives you the calories you actually burn plus a starter plan. Then put it to work with a coach in your messaging app: WhatsApp is the easiest way in, and it also works over SMS in the US. Already know your numbers? Head to https://nanorhino.com/message and pick WhatsApp to jump straight in.

Do I need to download an app?

No. NanoRhino lives in your messaging app — WhatsApp is the easiest way in, and it also works over SMS. We also offer an optional iOS app for users who prefer it, but it's not required.

Is there a message limit? What does it cost?

Messaging NanoRhino is free for up to 50 messages per day. On SMS, standard carrier message and data rates may apply. If you exceed your daily free allowance, additional usage fees may apply — we'll always notify you before any charge.

How do I unsubscribe?

Reply STOP at any time to unsubscribe. Reply HELP for assistance. You can re-enroll anytime by texting START again.

What is Link Heart Limited?

Link Heart Limited is an AI health technology company based in Houston, Texas. We build NanoRhino, an AI-powered weight loss companion that provides personalized nutrition coaching with a unique pay-for-results model.

NanoRhino is an AI weight loss coach. Think of it as a personal AI nutritionist, AI dietitian, and AI calorie counter rolled into one. It starts with a free TDEE calculation, turns that into a personalized plan, and then coaches you right in your messaging app — answering questions, logging meals you send or photograph, and adjusting as you go. No app required. You only pay $10 per pound you actually lose.

Is NanoRhino a free AI weight loss coach?

Texting NanoRhino is free for up to 50 messages per day, and you only pay if you actually lose weight — $10 per pound, capped at $500 total. There's no subscription, no upfront fee, and no charge if the weight doesn't come off. So functionally it's a free AI weight loss coach until you get results, then it's a results-based fee.

How does pay-for-results pricing work?

NanoRhino charges $10 per pound you lose, capped at $500 total — and that's the entire model. You pay at the moment you win: the weigh-in that crosses a milestone settles it right then, celebration and receipt in the same breath. Three rules protect you. One: the same pound is never billed twice — we bill against the lowest weight you've been billed at, so if some weight comes back and you lose it again, the re-loss is free. Two: no progress, no charge — plateaus cost nothing, and there's no subscription running in the background. Three: your total is capped at $500 — lose more, pay nothing more. If you don't lose weight, you never pay a cent. Full details at https://nanorhino.com/pricing. Billing questions anytime: support@nanorhino.com.

What if I regain some weight — do I ever pay for the same pounds twice?

Never. We track the lowest weight you've been billed at, and only pounds below it are ever billed. Say you start at 200 lb and reach 190: that's 10 pounds, $100, and 190 becomes your billing floor. If you bounce to 195 and work back down to 190, those 5 pounds are free — you already paid for them once. Nothing new is billed until you go below 190. This is deliberate: much of the weight-loss industry makes its money from the regain-and-restart cycle. We only earn on new progress — it keeps us on your side of the scale, not across from it.

Is NanoRhino private and secure?

Yes. NanoRhino is a private, judgment-free space — your conversations live in your messaging app. There are no social feeds, no posting, and no sharing. Your health data is encrypted, never sold, never shared with third parties, and never used for advertising. You can request deletion of all your data at any time.

How is NanoRhino different from other weight-loss tools?

Most apps make you tap through screens to log calories or follow generic meal plans. NanoRhino is a conversation: text a meal photo and get a calorie estimate back; vent about a hard day and get coached through it. It's like having a private nutrition coach on speed dial — at a fraction of the cost.

How is NanoRhino different from apps like MyFitnessPal or Cal AI?

Apps like MyFitnessPal and Cal AI are trackers — they tell you the calories in your meal and stop there. NanoRhino logs meals too (send or photo a plate in chat), but the product is the coaching: it sets your targets, checks in weekly, explains why the scale moved, and adjusts your plan — and you only pay when you actually lose weight ($10 per pound, capped at $500). See the full breakdowns: NanoRhino vs MyFitnessPal, NanoRhino vs Cal AI, or browse all comparisons.

How is NanoRhino different from ChatGPT or other general AI assistants?

Three reasons. First, NanoRhino remembers everything you've told it — goals, allergies, last week's wins, your hard days. ChatGPT loses that context across conversations. Second, NanoRhino does the math reliably — calorie counts, macro targets, weekly weight-loss math — without the arithmetic slips a general model makes. Third, NanoRhino is purpose-tuned to be a non-judgmental coach. A general AI tries to be helpful, but it isn't designed to meet you consistently in cravings, shame, or setbacks the way a real coach should.

Where is Link Heart Limited located?

Link Heart Limited is headquartered in Houston, Texas, United States.

About | AI Nutrition Coach by Text | NanoRhino by Link Heart Limited

Link Heart Limited is an AI health technology company headquartered in Houston, Texas. We build NanoRhino — an AI nutrition coach that lives in your messaging app. No app to download, no login to remember. Just message NanoRhino on WhatsApp, and a real coach is on the other end of the line.

Our mission

People don't fail at weight loss because they don't know the rules. They fail because at 9pm, standing in front of the fridge, they're alone. The cheapest, most reliable way to reach someone in a hard moment isn't an app — it's a text. So we made the coach text you back.

A target that's measured, not guessed

Every calorie calculator on the internet runs the same formula: height, weight, age, activity — out comes an estimate. It's a fine starting point. It also isn't your metabolism.

NanoRhino treats that first number as exactly what it is — a starting point. As you text your meals and step on the scale, your coach measures what your body actually burns and recalculates your daily target every week from your own logged meals and weigh-ins. Meaningful changes are announced; small tunes land in your Sunday report; the target never drops below a safety floor. A few weeks in, the number guiding your weight loss isn't a formula's guess anymore — it's yours.

That closed loop is the product: a calorie deficit built on measured numbers, and a coach who keeps it honest.

Long-term over shortcuts

Our compass is long-term. We don't sell shortcuts. We don't shame. We don't profit until the weight is actually off. That's why our pricing is $10 per pound lost, capped at $500 — payment only when results are real. Every product decision optimizes for sustainable behavior change, not engagement metrics.

What NanoRhino does

Everything a real nutrition coach does, delivered over text:

Personalized weight-loss plan. Built around your goal, schedule, and favorite foods — with a daily target recalculated every week from your own logged meals and weigh-ins.
Daily meal reminders. Gentle check-ins, never nagging.
Photo calorie counting. Snap a meal, get calorie and macro estimates back in seconds.
Exercise plan creation. Movement that fits your day, your energy, your goal.
Encouragement & accountability. Wins celebrated, hard days listened to — never with shame.
Persistent memory. We remember everything you tell us. The conversation gets smarter every time.

Who builds it

NanoRhino is built by a two-person founding team: Vincent Xia (founder & CEO) and Xiaomeng Li (co-founder & CTO), who leads product and engineering.

Privacy

Your health data is sacred. Four explicit commitments:

Encrypted in transit and at rest.
Never sold — to data brokers, advertisers, insurers, or anyone else.
Never shared with third parties for their own purposes.
Never used for advertising. Your data doesn't power ads, anywhere.

You can request deletion of all your personal data at any time, no questions asked. Reach us at our contact page or via the privacy policy.

Contact

Link Heart Limited is based in Houston, Texas. You can reach us through our contact page, or connect on LinkedIn.

Technology that warms hearts.