Claude vs ChatGPT: Fitness tracker with food logging and calorie burn for weight. Join the debate.: Fitbit Charge 6

For a 28-year-old starting out, the Fitbit Charge 6 is the strongest pick here. The food logging inside the Fitbit app is genuinely good — large database, quick barcode scanning — and calorie burn tracking is reliable enough to build habits around without overwhelming you with data you don't need yet. The main alternative worth knowing is the Garmin Forerunner 55, which has better GPS and workout tracking, but the food logging lives in a separate app (MyFitnessPal) and that friction matters when you're building a new habit. Keeping sleep, steps, calories burned, and food in one place wins at the start. Fitbit Charge 6 is the call. Around £140–£160 in the UK, less in the US.

Fair challenge. Battery life on the Charge 6 is around 7 days with typical use, dropping to roughly 4-5 days with GPS active on outdoor walks — solid enough that you're not charging it every night. It's water-resistant to 50 metres, so sweat and rain aren't a concern. For home workouts it handles well — automatic workout detection is reliable and heart rate tracking during HIIT or circuit training is accurate enough for calorie burn purposes. Where it does fall short outdoors versus a Garmin is GPS accuracy on longer or more technical routes. For walking and home workouts at this stage, that gap doesn't matter. If they were trail running or cycling seriously, I'd revisit — but for the stated use case, the Charge 6 holds up.

Optical heart rate tracking on the Charge 6 — like all wrist-based trackers — lags during rapid intensity changes, so a circuit workout with bursts of effort will produce some inaccuracy. Calorie estimates can be off by 10-20% during those transitions. That's a real limitation worth naming honestly. But here's the context that matters: for a 28-year-old starting a weight loss journey, calorie burn figures are directional guides, not precise inputs. Consistency of logging and trend-tracking over weeks matters far more than precision on any single workout. Final recommendation: Fitbit Charge 6. The integrated food logging, reliable daily calorie burn trends, and single-app experience outweigh the heart rate lag limitation for this specific person at this specific stage. It's the right tool for building the habit first.