Diet adherence is not “perfect eating” — it’s repeatable behavior

A diet plan works on paper when it creates the right energy balance and meets your nutrition needs. In real life, the plan only works if you can repeat it. That’s why adherence is one of the strongest predictors of long‑term results. The best plan is the one you can do on busy days, travel days, and stressful days — not just on perfect Mondays.

This calculator converts a messy week into a clean score by measuring the behaviors that most people can track without labs: (1) how many days you followed your plan, (2) how close you stayed to your calorie target, (3) protein consistency, and (4) the “support habits” that keep hunger and cravings manageable (sleep, hydration, activity).

The score is intentionally simple. It won’t diagnose metabolism. It won’t judge your food choices. It’s a dashboard that answers: “How repeatable was my week?” If your progress is slow, a low score tells you why. If your progress is good, a high score tells you what to protect.

How the Diet Adherence Score is calculated (0–100)

The total score is the sum of weighted components, capped between 0 and 100. Each component is converted to a 0–1 “subscore” and then multiplied by its weight. Penalties are applied last. Here is the exact structure:

• DaysOnPlanScore = (daysOnPlan ÷ 7) × 30
• CalorieAccuracyScore = (calorieAccuracy% ÷ 100) × 20
• ProteinScore = (proteinDays ÷ 7) × 15
• WholeFoodScore = (wholeFoodDays ÷ 7) × 10
• HydrationScore = min(waterLiters ÷ targetLiters, 1) × 5
• SleepScore = clamp((sleepHours − 5) ÷ 4, 0, 1) × 5
• StepsScore = clamp(steps ÷ 10000, 0, 1) × 10
• Penalty = min(bingeEpisodes × 2 + alcoholDays × 1, 5)

The hydration target is weight-based: targetLiters = weightKg × 0.033. That equals ~2.3L/day for a 70kg person. Sleep is scored from 5 to 9 hours because, for most adults, fewer than 5 hours consistently increases hunger and decreases impulse control, while 7–9 hours supports recovery and appetite regulation.

Penalties don’t “erase” your week. They simply recognize that binge-style episodes and alcohol days often lead to a chain reaction: poorer sleep, higher hunger, and less structure. If alcohol isn’t an issue for you, your penalty stays near zero.

Examples: what different scores look like

Example A: “Pretty good week” (Score around 75–85)

Let’s say you followed your plan 5 days, were roughly 70–80% accurate with calories (some meals out), hit protein 4 days, drank close to your water target, slept ~7 hours, and averaged 7–8k steps with one “blowout” day. That’s a classic “real life but still progressing” week. Your focus lever is usually either calorie accuracy or protein.

Example B: “Locked in” (Score 90+)

A 90+ week typically looks boring: 6–7 days on plan, consistent meals, protein most days, plenty of steps, good sleep, and very few chaotic days. People often call this “motivation,” but it’s usually environment + routine.

Example C: “Struggling week” (Score 50–60)

A score in the 50s usually means the plan is too strict, life is chaotic, or both. The fix is not more willpower. The fix is to make the plan easier and build one anchor habit: a consistent breakfast, a consistent lunch, or a daily walk.

How to use this like a coach (not like a judge)

The smartest way to use a score is to treat it like a weekly check-in: Measure → Identify the easiest lever → Improve one thing → Repeat. If you try to improve everything, you’ll improve nothing. If you improve one lever at a time, you get compounding progress.

• If your score is low: increase “days on plan” by making the plan simpler. Fewer rules, fewer decisions.
• If your score is mid: tighten one lever (usually calories or protein). Keep the rest stable.
• If your score is high: protect your routine. The goal is not perfection; the goal is repeatability.

You can also use the score to compare strategies. Try a different meal plan for a week, then compare your adherence score. The plan with the higher adherence score is usually the one that will win long-term, even if the “theoretical” plan looks better on paper.

Frequently Asked Questions

• Is a higher score always better?

  Generally yes, but only if it’s sustainable. A score of 80 repeated for 8 weeks beats a score of 95 for 6 days followed by burnout.

• What score should I aim for?

  Many people see solid progress at 70–85. If you’re cutting aggressively, aim higher. If life is stressful, aim for a sustainable 65–75.

• What if I don’t track calories?

  Use your best estimate for calorie accuracy based on how consistent your portions and meal structure were. Think “how often did I drift off-plan?”

• Why is hydration based on weight?

  Body size influences fluid needs. The target here is a simple rule of thumb (0.033 L/kg/day). Adjust for heat, sweat, and medical guidance.

• Why include alcohol and binge episodes?

  Not to shame you — to identify patterns. These events often reduce sleep quality and increase next-day cravings. The penalty is capped to keep it proportional.

• Can I use this while bulking?

  Yes. Bulking also requires adherence: consistent surplus, consistent protein, and consistent training. The same behavior logic applies.

• How often should I calculate my score?

  Weekly is ideal. Daily scoring can feel obsessive and noisy; weekly scoring captures the trend and helps you set a clear focus lever.