beta
Body Weight Interpreter

Analyzes body weight using multiple indexes, evaluates its impact on longevity, and calculates the optimal weight. Provides evidence-based nutrition and weight-loss recommendations.
Enter values
all fields are optional
 
Value
Unit
Gender
 
Weight
Height
Body fat
Waist circumference
This tool is for informational purposes only and not intended for diagnosis.
BMI:
N/A
Body fat:
N/A
Waist-to-Height:
N/A
FFMI:
N/A

Overall assessment

Enter values to interpret

All cause mortality associated with this excess weight:
—
Reaching the recommended target weight could extend lifespan by approximately — years.

Nutrition recommendation

For weight loss in individuals at high risk for diabetes

Protein intake

1.5g per 1kg of when combined with moderate exercise

—
per day

Fiber intake

For satiety and improving postprandial hyperglycemia

50g
per day

Healthy Weight Targets

MethodologyTarget Weight
Weight at BMI 21
A BMI between 20 and 22 was associated with the lowest all-cause mortality risk among healthy never-smokers in a large meta-analysis of 30.3 million participants.

To calculate, enter value for Height.

—
Weight at BMI 25
Although a BMI of 25 falls at the top of the “healthy range”, it is associated with a 5x risk of diabetes and a 40% higher risk of coronary heart disease compared to a BMI of 21.

To calculate, enter value for Height.

—
Lean Mass Sparing Target Weight
Recommended
This method models realistic weight loss, where the share of weight lost from fat gradually decreases as a person gets leaner. It assumes high lean-mass preservation through resistance training and adequate protein intake, then calculates the weight at which body fat would reach 16% for men or 21% for women.

To calculate, enter values for: Weight, Height, Body fat, Gender.

—

Anthropometric Biomarkers and Ratios

Body fat: 000%

Total body fat percentage is a better predictor of cardio-metabolic risk than BMI.

BMI: 000 kg/m²

Body Mass Index doesn't distinguish between fat and muscle mass, so it is misleading in body building athletes. But works well for the general population.
18.5
25
30
35
40

Waist-to-Height: 000 cm/cm

Waist-to-Height Ratio is a better predictor of cardio-metabolic risk than BMI.
0.3
0.5
0.55
0.65

FFMI: 000 kg/m²

Fat-Free Mass Index is used to evaluate whether an individual has adequate muscle mass for their height. Values above 25 are suspicious for anabolic steroid use.

Why this beats ChatGPT

Body Weight Interpreter computes the all-cause-mortality hazard ratio for the current body weight and proposes several target weights side by side, each derived from a different methodology, including a recommended Lean-Mass-Sparing target based on a target body-fat percentage that is gender-specific. For each target, it reports the exact kg to lose, the estimated months to reach it, and the resistance-training intensity required. It also outputs personalized daily protein and fiber intake based on adjusted body weight. Chatbots don't do that.

All research is done by humans. AI helps with coding and refining text for better readability.

  • Optimal ranges, not just “normal”

    Generic AI uses normal lab ranges (based on population averages). This tool uses functional, best-outcome targets.

  • Evidence-locked math. Not hallucinations

    Generic AI chatbots don’t know which calculated indices are best or their optimal cutoff values.

  • Quantified impact on longevity

    See the estimated impact of body weight on all-cause mortality and longevity.

  • Privacy by default

    Everything happens in your browser and no personal or medical information leaves your computer.

About the site author

My personal mission is to extend human lifespan by collectively adding 1 million years to people's lives.

That’s why I made this site 100% free, no sign-up, no email. Just instant results.

Zsolt Szabo
Zsolt Szabo
Precision Health Consultant for Longevity Clinics

How would you improve this tool ?

Any feedback is welcome at .