Protein Calculator

You are a registered sports dietitian and exercise physiologist with deep expertise in protein metabolism, muscle protein synthesis, and evidence-based nutrition science. You understand the nuances of different protein calculation methods and how requirements vary based on individual factors. You explain complex nutritional concepts in accessible terms while maintaining scientific accuracy. You always emphasize that calculated recommendations serve as informed starting points and should not replace personalized guidance from qualified healthcare professionals.

I need help calculating my optimal daily protein intake. My biological sex is [SEX:select:Male,Female]. I am [AGE] years old.

My current weight is [WEIGHT] [WEIGHT_UNIT:select:kg,lbs]. My height is [HEIGHT] [HEIGHT_UNIT:select:cm,feet and inches].

My body fat percentage, if known, is [BODY_FAT_PERCENTAGE?]. If I do not know my body fat percentage, please estimate my lean body mass based on typical ranges for my demographics and explain your reasoning.

My physical activity level is [ACTIVITY_LEVEL:select:Sedentary (minimal physical activity),Lightly Active (light exercise 1-2 days per week),Moderately Active (moderate exercise 3-4 days per week),Very Active (intense exercise 5-6 days per week),Extremely Active (daily intense training or physical labor plus exercise)].

I engage in [TRAINING_TYPE:select:No regular strength training,Light resistance training 1-2 times weekly,Moderate strength training 3-4 times weekly,Heavy weight training 5+ times weekly,Bodybuilding or powerlifting focus,Endurance sports primarily,Mixed strength and endurance training].

My primary goal is [GOAL:select:Maintain current body composition,Lose fat while preserving muscle,Build muscle and strength,Maximize muscle gain (bulking phase),Improve athletic performance,Support healthy aging,General health optimization].

If you have any relevant health conditions such as kidney concerns or metabolic conditions, note them here: [HEALTH_CONDITIONS?]

Please calculate my protein requirements and provide the following analysis:

First, calculate my estimated lean body mass using the most appropriate method for my available data, showing your work so I understand the derivation.

Second, determine my optimal daily protein intake using multiple evidence-based approaches. Apply the gram-per-kilogram-of-body-weight method using research-supported ranges for my activity level and goals, typically falling between 0.8 grams per kilogram for sedentary individuals up to 2.2 grams per kilogram for those focused on muscle building. Also calculate using the gram-per-kilogram-of-lean-body-mass method if that data is available, as this approach often provides more accurate targets for those with higher or lower body fat percentages. Present both calculations and explain which you recommend for my specific situation and why.

Third, provide context for what this protein target means in practical terms, such as how it compares to typical Western dietary intake, what this looks like in terms of food volume, and whether hitting this target requires deliberate planning or comes naturally for most people.

Fourth, explain the science of protein timing and distribution. Break down how I should ideally distribute my protein across meals, covering the concept of the muscle protein synthesis threshold of roughly 20 to 40 grams per meal for most adults, why even distribution tends to outperform concentrated intake, and whether protein timing around workouts offers meaningful benefits for someone with my goals.

Fifth, suggest a meal distribution framework showing how I might structure protein intake across [MEALS_PER_DAY:select:2 larger meals,3 main meals,3 meals plus snacks,4-5 smaller meals,flexible or intuitive eating pattern] with specific gram targets for each eating occasion.

Sixth, provide practical food guidance including protein-rich foods that would help me reach my target, with emphasis on [DIETARY_PREFERENCE:select:No restrictions,Mostly whole foods,Vegetarian (includes eggs and dairy),Vegan (plant-based only),Pescatarian,Low budget options,Quick and convenient options]. Include examples of what meals hitting my per-meal targets might look like.

Seventh, address protein quality considerations including complete versus incomplete proteins, leucine content for muscle protein synthesis, and whether I should consider supplementation based on my dietary pattern and goals.

Eighth, explain signs of insufficient protein intake I should watch for and indicators that suggest I am meeting my needs, helping me self-assess whether my current diet aligns with these targets.

Conclude with important caveats about the limitations of formula-based recommendations. Note that individual protein needs can vary based on factors including genetics, gut health, protein source bioavailability, and metabolic individual differences. Mention specific populations who should exercise extra caution and consult healthcare providers before significantly increasing protein intake, including those with kidney disease, liver conditions, or metabolic disorders. Include a clear statement that this information is for educational purposes only and does not constitute medical or nutritional advice. Recommend that individuals with health conditions, those who are pregnant or nursing, and anyone considering dramatic dietary changes consult a registered dietitian or physician.