Protein Intake Calculator for Weight Loss Female

Calculate your personalized daily protein target to support weight loss goals effectively. Protein is crucial for satiety, muscle preservation, and metabolism during a calorie deficit.

Calculate Your Daily Protein Needs

What is a Protein Intake Calculator for Weight Loss (Female)?

A **protein intake calculator for weight loss female** is a specialized tool designed to help women determine the optimal amount of protein they should consume daily to support their weight loss objectives. Unlike generic calorie calculators, this tool focuses on the critical role of protein in a female weight loss journey. Protein is a macronutrient essential for numerous bodily functions, including muscle repair and growth, hormone production, and enzyme activity. During weight loss, maintaining adequate protein intake is particularly important for preserving lean muscle mass, enhancing satiety (feeling full), and supporting a healthy metabolism, all of which contribute to more sustainable and effective fat loss.

Who should use it:

• Women aiming to lose weight, whether it's a few pounds or a significant amount.
• Individuals who want to ensure they are consuming enough protein to support muscle health while in a calorie deficit.
• Those looking to increase feelings of fullness and reduce cravings during their weight loss program.
• Women interested in understanding how macronutrient balance, particularly protein, impacts their weight loss results.

Common misconceptions:

• Myth: Eating more protein will automatically build large muscles. Reality: While protein is crucial for muscle repair and growth, building significant muscle mass also requires specific resistance training and often a calorie surplus. For weight loss, protein helps preserve muscle.
• Myth: You need excessive protein (e.g., 3g/kg) for weight loss. Reality: While higher protein intake is beneficial, there are diminishing returns. Recommendations for weight loss typically range from 1.6 to 2.2 grams per kilogram of body weight, sometimes slightly higher depending on activity and individual response. Extremely high intakes are often unnecessary and can displace other essential nutrients.
• Myth: Protein intake is the same for men and women. Reality: While the general principles are similar, women often have different hormonal profiles, body compositions, and metabolic rates that can influence their specific needs, especially during weight loss. This calculator is tailored for females.
• Myth: All protein sources are equal. Reality: While many foods provide protein, the quality (completeness of amino acids), accompanying nutrients (vitamins, minerals, fiber), and digestibility vary.

Protein Intake Calculator for Weight Loss (Female) Formula and Mathematical Explanation

The **protein intake calculator for weight loss female** utilizes a multi-step process to arrive at a personalized daily protein target. It begins by estimating the user's energy expenditure and then allocates a significant portion of the required calories to protein, considering weight loss goals and recommended intake ranges.

Step-by-Step Derivation:

1. Basal Metabolic Rate (BMR) Calculation: This is the foundational step, calculating the calories burned at rest. Two common formulas are used:
   • Revised Harris-Benedict Equation (for women): BMR = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) – (4.330 × age in years)
   • Mifflin-St Jeor Equation (for women): BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
   The calculator allows the user to select which formula to use.
2. Total Daily Energy Expenditure (TDEE) Calculation: The BMR is then adjusted for activity level using an activity factor:
   TDEE = BMR × Activity Factor
   Activity Factors typically are:
   • Sedentary: 1.2
   • Lightly Active: 1.375
   • Moderately Active: 1.55
   • Very Active: 1.725
   • Extra Active: 1.9
3. Calorie Deficit Calculation: To lose weight, a calorie deficit is required. One kilogram of fat is approximately equivalent to 7700 kcal. A weekly weight loss goal is translated into a daily deficit:
   Daily Deficit (kcal) = (Weekly Weight Loss Goal [kg] × 7700 kcal/kg) / 7 days
   For a goal of 0.5 kg/week: Daily Deficit = (0.5 × 7700) / 7 = 550 kcal/day.
4. Target Calorie Intake: The daily calorie target for weight loss is determined by subtracting the daily deficit from the TDEE:
   Target Calories = TDEE – Daily Deficit
5. Protein Intake Calculation: This is the core focus. Protein intake is calculated using a combination of a percentage of target calories and a grams-per-kilogram target, adjusted for weight loss considerations.
   A common recommendation for weight loss is 1.6 to 2.2 grams of protein per kilogram of body weight. For females aiming for weight loss, targeting around 1.8g/kg is a good starting point, but it can be adjusted.
   Protein (grams) = Target Calories × Protein Percentage / 4 kcal/g
   OR
   Protein (grams) = Selected Protein g/kg × Current Weight (kg)
   The calculator may prioritize a g/kg target and then calculate the percentage, or vice-versa, ensuring it falls within a healthy and effective range (e.g., 30-40% of target calories or 1.6-2.2 g/kg). The chosen method aims for a balance supporting satiety and muscle preservation during the deficit.

Variable Explanations:

Variable	Meaning	Unit	Typical Range / Notes
Weight	Current body weight	kg	Positive number, e.g., 50-150 kg
Height	Body height	cm	Positive number, e.g., 140-190 cm
Age	User's age	Years	Positive integer, e.g., 18-80 years
Activity Level	Estimated physical activity	Categorical	Sedentary, Lightly Active, Moderately Active, Very Active, Extra Active
BMR	Basal Metabolic Rate	kcal/day	Estimated calories burned at rest
TDEE	Total Daily Energy Expenditure	kcal/day	Estimated total calories burned daily
Weight Loss Goal	Desired weekly weight loss rate	kg/week	0.25, 0.5, 0.75, 1.0 kg/week
Daily Deficit	Required daily calorie deficit	kcal/day	Calculated based on goal (e.g., 250-1000 kcal/day)
Target Calories	Daily calorie intake goal for weight loss	kcal/day	TDEE – Daily Deficit
Protein Intake (g)	Recommended daily protein consumption	grams/day	Calculated based on target calories and g/kg recommendations
Protein Percentage	Proportion of protein in the diet	%	Typically 30-40% for weight loss
Protein g/kg	Grams of protein per kilogram of body weight	g/kg	Typically 1.6-2.2 g/kg for weight loss

Practical Examples (Real-World Use Cases)

Understanding the **protein intake calculator for weight loss female** through examples makes its application clearer.

Example 1: Sarah, aiming for moderate weight loss

Sarah is 32 years old, weighs 75 kg, and is 168 cm tall. She works a desk job but exercises moderately 3-4 times a week (e.g., jogging, strength training). She wants to lose about 0.5 kg per week sustainably.

• Inputs:
  • Activity Level: Moderately Active
  • Current Weight: 75 kg
  • Height: 168 cm
  • Age: 32 years
  • BMR Method: Mifflin-St Jeor
  • Weight Loss Goal: 0.5 kg/week
• Calculation Process (Simplified):
  • BMR (Mifflin-St Jeor for women): (10 * 75) + (6.25 * 168) – (5 * 32) – 161 = 750 + 1050 – 160 – 161 = 1479 kcal
  • TDEE (Moderately Active): 1479 * 1.55 = 2292 kcal
  • Daily Deficit for 0.5 kg/week: (0.5 * 7700) / 7 = 550 kcal
  • Target Calories: 2292 – 550 = 1742 kcal
  • Protein Target (using ~1.8g/kg): 1.8 g/kg * 75 kg = 135 grams of protein
  • Check Protein Percentage: (135g * 4 kcal/g) / 1742 kcal ≈ 31%
• Calculator Output:
  • Estimated BMR: ~1479 kcal
  • TDEE: ~2292 kcal
  • Calorie Deficit: ~550 kcal
  • Target Macronutrient Split (Example): ~1742 kcal (Protein: 135g, Fat: 65g, Carbs: 145g – based on a common split)
  • Primary Result: Daily Protein Target: ~135 grams

Interpretation: Sarah should aim for approximately 135 grams of protein per day to support her goal of losing 0.5 kg per week while preserving muscle mass and managing hunger.

Example 2: Emily, focused on higher protein for satiety

Emily is 28 years old, weighs 65 kg, and is 160 cm tall. She works from home and only manages light exercise 1-2 times a week. She's looking for a more aggressive weight loss of 0.75 kg per week and wants to maximize protein for satiety.

• Inputs:
  • Activity Level: Lightly Active
  • Current Weight: 65 kg
  • Height: 160 cm
  • Age: 28 years
  • BMR Method: Revised Harris-Benedict
  • Weight Loss Goal: 0.75 kg/week
• Calculation Process (Simplified):
  • BMR (Harris-Benedict for women): 447.593 + (9.247 * 65) + (3.098 * 160) – (4.330 * 28) = 447.593 + 600.055 + 495.68 – 121.24 = 1422 kcal
  • TDEE (Lightly Active): 1422 * 1.375 = 1955 kcal
  • Daily Deficit for 0.75 kg/week: (0.75 * 7700) / 7 = 825 kcal
  • Target Calories: 1955 – 825 = 1130 kcal (Note: This is quite low, emphasizing caution for aggressive deficits)
  • Protein Target (using ~2.0g/kg for higher satiety): 2.0 g/kg * 65 kg = 130 grams of protein
  • Check Protein Percentage: (130g * 4 kcal/g) / 1130 kcal ≈ 46% (This highlights a high protein percentage which might be difficult to sustain or fill with micronutrients)
• Calculator Output:
  • Estimated BMR: ~1422 kcal
  • TDEE: ~1955 kcal
  • Calorie Deficit: ~825 kcal
  • Target Macronutrient Split (Example): ~1130 kcal (Protein: 130g, Fat: 30g, Carbs: 70g – adjusted for high protein)
  • Primary Result: Daily Protein Target: ~130 grams

Interpretation: Emily's aggressive goal requires a significant calorie deficit. The calculator suggests around 130 grams of protein. While this provides high satiety, the very low overall calorie target of 1130 kcal should be approached with caution. It might be beneficial for Emily to consider a slightly slower weight loss rate (0.5 kg/week) to allow for a more balanced and sustainable calorie intake and nutrient profile.

How to Use This Protein Intake Calculator for Weight Loss (Female)

Using the **protein intake calculator for weight loss female** is straightforward and provides valuable insights for your weight loss journey. Follow these steps:

1. Input Your Data:
   • Activity Level: Honestly assess your weekly exercise routine and select the option that best describes your lifestyle.
   • Current Weight: Enter your weight in kilograms (kg).
   • Height: Enter your height in centimeters (cm).
   • Age: Provide your age in years.
   • BMR Calculation Method: Choose either the Revised Harris-Benedict or Mifflin-St Jeor equation. Mifflin-St Jeor is often considered more accurate for most individuals.
   • Weight Loss Goal: Select your desired weekly weight loss rate. A sustainable rate is typically 0.5 kg per week. More aggressive goals require larger calorie deficits and may be harder to maintain.
2. Press 'Calculate': Once all fields are filled, click the "Calculate" button.
3. Review Your Results:
   • Primary Result (Daily Protein Target): This is the main output, shown in grams per day. This is your recommended protein intake.
   • Estimated BMR: The number of calories your body burns at rest.
   • TDEE: Your total estimated daily calorie burn, accounting for your activity level.
   • Calorie Deficit: The daily calorie reduction needed to meet your weight loss goal.
   • Target Macronutrient Split: An example of how your target calories might be divided among protein, fat, and carbohydrates. Note that this calculator prioritizes protein.
   • Key Assumptions: These provide context on the factors used in the calculation, such as the activity factor and the specific protein recommendations (g/kg and percentage).
4. Interpret and Apply: Use the calculated daily protein target (in grams) to guide your food choices throughout the day. Aim to distribute your protein intake across your meals and snacks. For instance, if your target is 130g, aim for roughly 30-40g per main meal.
5. Use 'Copy Results': If you want to save or share your calculated figures, use the "Copy Results" button.
6. Use 'Reset': If you need to start over or change your inputs, click "Reset" to return to default or sensible starting values.

How to Read Results and Decision-Making Guidance:

The primary result is your actionable target: **grams of protein per day**. This number is derived from balancing your energy needs, weight loss goals, and the benefits of higher protein intake. Remember that this is an estimate. Your body's response may vary.

• Listen to Your Body: If you feel excessively fatigued or hungry, your calorie deficit might be too aggressive, or your nutrient balance needs adjustment. Consider a slightly slower weight loss goal.
• Focus on Quality Protein: Prioritize lean sources like chicken breast, turkey, fish, lean beef, eggs, Greek yogurt, tofu, beans, and lentils.
• Adjust Based on Progress: Monitor your weight loss progress. If you're losing too quickly or too slowly, you may need to adjust your overall calorie intake slightly, while keeping protein high.
• Consult Professionals: For personalized advice, especially if you have underlying health conditions, consult a registered dietitian or healthcare provider.

Key Factors That Affect Protein Intake Calculator Results

Several factors influence the accuracy and suitability of the results from a **protein intake calculator for weight loss female**. Understanding these can help you interpret your personalized target more effectively:

1. Body Composition (Muscle vs. Fat Mass): The calculator uses total body weight. However, protein needs are more closely tied to lean body mass. If you have a higher percentage of muscle mass, your actual protein needs might be slightly higher than calculated, especially if you are very active. Conversely, if a large portion of your weight is adipose tissue, the calculated grams/kg might be slightly higher than strictly necessary for muscle support but still beneficial for satiety and thermic effect during weight loss.
2. Activity Level Accuracy: The "Activity Level" input is a broad categorization. The precise energy expenditure varies greatly based on the type, intensity, and duration of exercise, as well as non-exercise activity thermogenesis (NEAT – fidgeting, walking, daily movements). Overestimating activity leads to a higher TDEE and potentially a higher calorie target, making weight loss slower.
3. Metabolic Adaptation: Over time, especially during prolonged calorie restriction, the body can adapt by slowing down metabolism. The TDEE calculated by standard formulas might become less accurate. Regular reassessment and potential adjustments to calorie intake or activity are crucial.
4. Hormonal Fluctuations (Female Specific): Women experience hormonal cycles (menstrual cycle) that can influence appetite, water retention, and energy levels. These fluctuations can temporarily affect perceived hunger and metabolic rate, meaning your exact needs might vary slightly throughout the month.
5. Dietary Preferences and Adherence: The calculator provides a target, but adherence is key. If your calculated protein target is very high and difficult to achieve with foods you enjoy or can access, it might lead to frustration and reduced compliance. The calculator's flexibility in setting protein percentage or g/kg can help, but realistic food choices matter.
6. Health Conditions & Medications: Certain health conditions (e.g., kidney issues, thyroid disorders) and medications can significantly impact metabolism, nutrient absorption, and protein requirements. This calculator does not account for such specific medical situations and should not replace professional medical advice.
7. Age-Related Metabolic Changes: While age is an input, the rate of metabolic decline can vary. Older individuals may experience a more significant decrease in BMR and muscle mass, potentially requiring adjustments to calorie and protein intake strategies.
8. Digestive Efficiency and Nutrient Absorption: Individual differences in digestion can affect how well protein and other nutrients are absorbed and utilized. While not directly factored into standard calculations, it's a biological variable.

Frequently Asked Questions (FAQ)

Q1: Is the calculated protein intake safe for kidneys?

For individuals with healthy kidneys, the recommended protein intake for weight loss (typically 1.6-2.2 g/kg) is generally considered safe. However, if you have pre-existing kidney conditions, it's crucial to consult your doctor or a registered dietitian before significantly increasing your protein intake.

Q2: Can I hit my protein goal with plant-based foods?

Yes, absolutely! While achieving high protein intake solely from plants requires careful planning, it's very possible. Focus on incorporating sources like lentils, beans, chickpeas, tofu, tempeh, edamame, nuts, seeds, and whole grains. Combining different plant proteins throughout the day can help ensure you get a complete amino acid profile.

Q3: What happens if I consume more protein than recommended?

Consuming slightly more protein than recommended (e.g., a few extra grams) is usually not harmful for healthy individuals and can further enhance satiety and muscle preservation. However, excessively high protein intake can displace other essential macronutrients (carbohydrates and fats) and micronutrients, potentially leading to nutrient deficiencies if not balanced. It also requires more calories to digest (thermic effect), which might slightly hinder weight loss if not accounted for.

Q4: Should I adjust protein intake based on my menstrual cycle?

Some women find their appetite and cravings change during different phases of their menstrual cycle. While your core protein needs remain relatively stable, you might find it helpful to slightly adjust your food choices or meal timing to manage hunger effectively. For example, focusing on protein and fiber during the luteal phase might help with cravings.

Q5: Does the calculator account for lean body mass vs. total weight?

This calculator primarily uses total body weight for simplicity and broad applicability. While lean body mass is a more precise indicator, obtaining accurate body composition measurements can be difficult. The recommended protein ranges (1.6-2.2 g/kg) are generally sufficient even when considering lean mass, especially during weight loss when the goal is to preserve existing muscle. Some calculators might offer options to input lean body mass directly if known.

Q6: How quickly should I expect to lose weight with this calculator's recommendations?

The calculator provides a calorie deficit aimed at a specific weekly weight loss. For a 0.5 kg/week goal, expect roughly 1-2 lbs of fat loss per week. Remember that actual results can vary due to water fluctuations, metabolic adaptation, and adherence to the plan. Faster loss rates (0.75-1 kg/week) are possible but require a larger deficit and may be harder to sustain.

Q7: What if my target calorie intake is very low (e.g., under 1200 kcal)?

If your calculated target calorie intake falls below 1200 kcal per day, it is advisable to proceed with caution. Such low intakes can be difficult to sustain, may not provide adequate essential nutrients, and can lead to significant muscle loss and metabolic slowdown. Consider a slower weight loss goal (e.g., 0.25 or 0.5 kg/week) to achieve a more balanced and sustainable calorie target. Consulting a healthcare professional is highly recommended in these cases.

Q8: How does protein intake affect satiety?

Protein is the most satiating macronutrient. It takes longer to digest than carbohydrates and fats, and it influences several hormones involved in appetite regulation (like ghrelin and peptide YY). Consuming adequate protein helps you feel fuller for longer periods, reducing overall hunger and making it easier to stick to a calorie deficit, which is crucial for successful weight loss.

Related Tools and Internal Resources

• Macronutrient Calculator

  Determine the ideal balance of carbohydrates, fats, and proteins for your fitness goals, including weight loss.

• BMI Calculator

  Calculate your Body Mass Index (BMI) to get a general idea of your weight category relative to your height.

• Calorie Deficit Calculator

  Estimate the daily calorie deficit needed to achieve your desired weekly weight loss.

• Water Intake Calculator

  Calculate your personalized daily water intake recommendation for optimal health and hydration.

• Nutrition Guide for Weight Loss

  Learn fundamental principles of nutrition for effective and sustainable weight management.

• Exercise Calorie Calculator

  Estimate the calories burned during various physical activities to better manage your energy balance.

targetCalories * 0.8) { // If protein is >80% of calories, it's too high finalProteinGrams = Math.round(targetCalories * 0.8 / 4); } finalProteinGrams = Math.max(finalProteinGrams, 50); // Absolute minimum protein grams finalProteinGrams = Math.round(finalProteinGrams); var proteinPercentage = Math.round((finalProteinGrams * 4) / targetCalories * 100); var proteinGPerKgActual = Math.round(finalProteinGrams / weightKg * 100) / 100; // Example Macronutrient Split (approximate, assuming typical ratios for weight loss) var fatGrams = Math.round((targetCalories * 0.30) / 9); // ~30% fat var carbGrams = Math.round((targetCalories – (finalProteinGrams * 4) – (fatGrams * 9)) / 4); var macroSplit = finalProteinGrams + "g Protein (" + proteinPercentage + "%), " + fatGrams + "g Fat (~30%), " + carbGrams + "g Carbs (~" + Math.round(carbGrams * 4 / targetCalories * 100) + "%)"; document.getElementById('estimatedBmr').textContent = bmr + " kcal"; document.getElementById('tdee').textContent = tdee + " kcal"; document.getElementById('calorieDeficit').textContent = calorieDeficitPerDay + " kcal"; document.getElementById('primaryResult').textContent = finalProteinGrams + " g"; document.getElementById('macroSplit').textContent = macroSplit; document.getElementById('activityFactorAssumed').textContent = activityFactor; document.getElementById('proteinPercAssumed').textContent = proteinPercentage + "%"; document.getElementById('proteinGPerKgAssumed').textContent = proteinGPerKgActual + " g/kg"; updateChart(tdee, targetCalories, finalProteinGrams); } function copyResults() { var primaryResult = document.getElementById('primaryResult').textContent; var estimatedBmr = document.getElementById('estimatedBmr').textContent; var tdee = document.getElementById('tdee').textContent; var calorieDeficit = document.getElementById('calorieDeficit').textContent; var macroSplit = document.getElementById('macroSplit').textContent; var activityFactorAssumed = document.getElementById('activityFactorAssumed').textContent; var proteinPercAssumed = document.getElementById('proteinPercAssumed').textContent; var proteinGPerKgAssumed = document.getElementById('proteinGPerKgAssumed').textContent; var resultsText = "— Protein Intake Calculator Results —\n\n"; resultsText += "Primary Result: Daily Protein Target: " + primaryResult + "\n"; resultsText += "Estimated BMR: " + estimatedBmr + "\n"; resultsText += "Total Daily Energy Expenditure (TDEE): " + tdee + "\n"; resultsText += "Calorie Deficit for Goal: " + calorieDeficit + "\n"; resultsText += "Target Macronutrient Split (Example): " + macroSplit + "\n\n"; resultsText += "Key Assumptions:\n"; resultsText += "- Activity Factor: " + activityFactorAssumed + "\n"; resultsText += "- Protein Percentage of Target Calories: " + proteinPercAssumed + "\n"; resultsText += "- Protein g/kg target (adjusted): " + proteinGPerKgAssumed + "\n"; // Copy to clipboard navigator.clipboard.writeText(resultsText).then(function() { // Show success message briefly var copyButton = document.querySelector('button.success'); var originalText = copyButton.textContent; copyButton.textContent = 'Copied!'; copyButton.style.backgroundColor = 'var(–success-color)'; setTimeout(function() { copyButton.textContent = originalText; copyButton.style.backgroundColor = "; // Reset to original color }, 2000); }, function(err) { console.error('Failed to copy results: ', err); alert('Failed to copy results. Please copy manually.'); }); } function resetForm() { document.getElementById('activityLevel').value = 'moderate'; document.getElementById('weightKg').value = "; document.getElementById('heightCm').value = "; document.getElementById('age').value = "; document.getElementById('bmrMethod').value = 'harris-benedict'; document.getElementById('weightLossGoal').value = '0.5'; // Clear errors document.getElementById('weightKgError').textContent = "; document.getElementById('weightKgError').style.display = 'none'; document.getElementById('heightCmError').textContent = "; document.getElementById('heightCmError').style.display = 'none'; document.getElementById('ageError').textContent = "; document.getElementById('ageError').style.display = 'none'; // Clear results document.getElementById('estimatedBmr').textContent = "– kcal"; document.getElementById('tdee').textContent = "– kcal"; document.getElementById('calorieDeficit').textContent = "– kcal"; document.getElementById('primaryResult').textContent = "– g"; document.getElementById('macroSplit').textContent = "–"; document.getElementById('activityFactorAssumed').textContent = "–"; document.getElementById('proteinPercAssumed').textContent = "–"; document.getElementById('proteinGPerKgAssumed').textContent = "–"; // Clear and reset chart if (ctx) { ctx.clearRect(0, 0, canvas.width, canvas.height); } if (chartInstance) { chartInstance.destroy(); // Destroy previous chart instance if it exists chartInstance = null; } initializeChart(); // Re-initialize with default state } function initializeChart() { canvas = document.getElementById('energyBalanceChart'); if (!canvas) { console.error("Canvas element not found!"); return; } ctx = canvas.getContext('2d'); // Clear any previous chart drawing ctx.clearRect(0, 0, canvas.width, canvas.height); // Set default text for clarity before calculation ctx.font = "16px Segoe UI"; ctx.fillStyle = "#555"; ctx.textAlign = "center"; ctx.fillText("Enter details and click Calculate to see the chart.", canvas.width/2, canvas.height/2); } function updateChart(tdee, targetCalories, proteinGrams) { if (!ctx) { console.error("Canvas context not available."); return; } // Clear previous chart ctx.clearRect(0, 0, canvas.width, canvas.height); var chartWidth = canvas.width; var chartHeight = canvas.height; var barWidth = 40; var barSpacing = 60; var maxBarHeight = chartHeight – 50; // Reserve space for labels var maxValue = Math.max(tdee, targetCalories, proteinGrams * 4); // Use kcal for comparison var scale = maxBarHeight / maxValue; // Draw TDEE Bar var tdeeBarHeight = Math.round(tdee * scale); ctx.fillStyle = 'rgba(255, 99, 132, 0.7)'; // Red for TDEE ctx.fillRect(chartWidth / 2 – barSpacing / 2 – barWidth, chartHeight – tdeeBarHeight, barWidth, tdeeBarHeight); ctx.fillStyle = '#333'; ctx.textAlign = 'center'; ctx.font = '14px Segoe UI'; ctx.fillText('TDEE', chartWidth / 2 – barSpacing / 2, chartHeight – tdeeBarHeight – 10); ctx.fillText(tdee + ' kcal', chartWidth / 2 – barSpacing / 2, chartHeight – tdeeBarHeight – 30); // Draw Target Calories Bar var targetCaloriesBarHeight = Math.round(targetCalories * scale); ctx.fillStyle = 'rgba(54, 162, 235, 0.7)'; // Blue for Target Calories ctx.fillRect(chartWidth / 2 + barSpacing / 2, chartHeight – targetCaloriesBarHeight, barWidth, targetCaloriesBarHeight); ctx.fillStyle = '#333'; ctx.fillText('Target Intake', chartWidth / 2 + barSpacing / 2, chartHeight – targetCaloriesBarHeight – 10); ctx.fillText(targetCalories + ' kcal', chartWidth / 2 + barSpacing / 2, chartHeight – targetCaloriesBarHeight – 30); // Draw Protein Bar (scaled in kcal) var proteinKcal = proteinGrams * 4; var proteinBarHeight = Math.round(proteinKcal * scale); ctx.fillStyle = 'rgba(75, 192, 192, 0.7)'; // Green for Protein ctx.fillRect(chartWidth / 2 + barSpacing / 2 + barWidth + barSpacing / 2, chartHeight – proteinBarHeight, barWidth, proteinBarHeight); ctx.fillStyle = '#333'; ctx.fillText('Protein', chartWidth / 2 + barSpacing / 2 + barWidth + barSpacing / 2, chartHeight – proteinBarHeight – 10); ctx.fillText(proteinGrams + ' g (' + Math.round(proteinKcal * 100 / targetCalories) + '%)', chartWidth / 2 + barSpacing / 2 + barWidth + barSpacing / 2, chartHeight – proteinBarHeight – 30); // Y-axis labels (optional, can be complex with pure canvas) ctx.fillStyle = '#333'; ctx.textAlign = 'right'; ctx.font = '12px Segoe UI'; ctx.fillText(maxValue.toFixed(0) + ' kcal', 50, 20); ctx.fillText((maxValue/2).toFixed(0) + ' kcal', 50, chartHeight / 2); ctx.fillText('0 kcal', 50, chartHeight – 10); // Labels for bars ctx.textAlign = 'center'; ctx.font = '14px Segoe UI'; ctx.fillStyle = '#333′; // Legend var legendY = chartHeight + 20; var legendSpacing = 150; ctx.font = '13px Segoe UI'; // TDEE Legend ctx.fillStyle = 'rgba(255, 99, 132, 0.7)'; ctx.fillRect(chartWidth / 2 – barSpacing / 2 – barWidth – legendSpacing, legendY, 15, 15); ctx.fillStyle = '#333'; ctx.fillText('TDEE', chartWidth / 2 – barSpacing / 2 – barWidth – legendSpacing + 25, legendY + 12); // Target Intake Legend ctx.fillStyle = 'rgba(54, 162, 235, 0.7)'; ctx.fillRect(chartWidth / 2 + barSpacing / 2 – legendSpacing, legendY, 15, 15); ctx.fillStyle = '#333'; ctx.fillText('Target Intake', chartWidth / 2 + barSpacing / 2 – legendSpacing + 25, legendY + 12); // Protein Legend ctx.fillStyle = 'rgba(75, 192, 192, 0.7)'; ctx.fillRect(chartWidth / 2 + barSpacing / 2 + barWidth + barSpacing / 2 – legendSpacing, legendY, 15, 15); ctx.fillStyle = '#333'; ctx.fillText('Protein Intake', chartWidth / 2 + barSpacing / 2 + barWidth + barSpacing / 2 – legendSpacing + 25, legendY + 12); } // Initial setup window.onload = function() { // Initialize default values if they exist or set placeholders document.getElementById('activityLevel').value = 'moderate'; document.getElementById('weightLossGoal').value = '0.5'; document.getElementById('bmrMethod').value = 'harris-benedict'; // Set initial placeholder text for results document.getElementById('estimatedBmr').textContent = "– kcal"; document.getElementById('tdee').textContent = "– kcal"; document.getElementById('calorieDeficit').textContent = "– kcal"; document.getElementById('primaryResult').textContent = "– g"; document.getElementById('macroSplit').textContent = "–"; document.getElementById('activityFactorAssumed').textContent = "–"; document.getElementById('proteinPercAssumed').textContent = "–"; document.getElementById('proteinGPerKgAssumed').textContent = "–"; // Initialize chart placeholder canvas = document.getElementById('energyBalanceChart'); if (canvas) { initializeChart(); } else { console.error("Canvas element 'energyBalanceChart' not found on load."); } // Add event listeners for real-time updates (optional, but good practice) var inputs = document.querySelectorAll('.loan-calc-container input, .loan-calc-container select'); for (var i = 0; i < inputs.length; i++) { inputs[i].addEventListener('input', function() { // Optionally disable calculation until button press, or calculate dynamically // For now, we rely on the Calculate button }); inputs[i].addEventListener('change', function() { // Recalculate on change for selects or when focus leaves number inputs // calculateProteinIntake(); // Uncomment for real-time calculation }); } };