The Zone Score (sometimes also called a Meal Score) quantifies how various foods and activities, in combination, affect your blood sugar levels. Scores range from 1 to 10, with 10 being an optimal glucose response. To calculate this score, we factor in how much and how quickly your glucose rises in the two hours following a logged meal.
Below, we explain the rationale behind Zone Scores and provide more detail about how we calculate them.
The feature and why we built it
A Zone is a roughly 2-hour window following a logged meal. The Zone Score aims to capture how your glucose levels respond to everything you do during that window (i.e., not just food but also physical activity, stress, and more).
This Zone Score rewards gradual, minimal changes in glucose because stable blood sugar supports quality of life in the short term and metabolic health in the long term.
“Levels developed ‘Zones’ to reflect that you don’t eat food in a vacuum,” says Azure Grant, Ph.D., research and design lead at Levels. “How your body responds to a given ingredient depends on what you do before and after you eat it: Are you consuming other foods? Going for a jog? Going to sleep? All those factors influence glycemic response, and your Zone score reflects that interaction.”
With the scoring system, the goal is not to achieve a perfect ten every time. Instead, by offering a simple record of each Zone, we hope to help members track how various combinations of foods and activities affect their bodies. You may find, for instance, that eating an apple on its own leads to a Zone Score of 6, but an apple followed by a walk generates an 8. This simple, quantitative difference may be a helpful way of thinking about how to approach your food and your days.
“The lesson doesn’t have to be never eat apples,” says Grant. “By thinking in terms of Zones, we hope people can appreciate, ‘Oh, if I’m eating an apple, I’ll need something else in that Zone as well—maybe a walk, or maybe some almond butter on the apple.”
Zones can also make it easier to observe trends in your days. For instance, you may notice that your morning Zones tend to be lower than your evening Zones or vice versa—an actionable insight that may motivate you to pay more attention to your choices early in the day.
Note that a Zone Score is not a diagnosis: A single score of 10 won’t make you metabolically fit, and a 3 doesn’t mean you’re ill. However, if you regularly score above 7 on your meals, you’re probably on the right track. If you regularly score 6 or below and experience energy swings, eating for more stable blood sugar may help.
Strategies for bumping up your Zones Scores include:
- Swapping out low-scoring foods for metabolically-healthy alternatives (e.g., try cauliflower rice in place of white rice).
- Adding fiber to your meal
- Pairing carbohydrates with fat and protein and/or eating them at the end of your meal
- Walking after your meal
- Avoiding stressors, particularly around mealtime
How we calculate scores
To calculate your Zone score, we look at two factors:
- How much your glucose rises following your meal. Though moderate changes in blood sugar are perfectly normal and healthy, big surges indicate that you’re consuming sugar faster than your body can use it. Smaller increases, therefore, earn higher scores.
- How quickly your glucose rises. Metabolically-healthy food tends to produce a slow, gentle rise in blood sugar. Carb-rich and processed foods, by contrast, quickly flood the bloodstream with glucose. To keep your score high, aim for less steep slopes on your glucose graph.
It is normal and healthy to see moderate changes in your glucose levels. Very large and steep spikes, however, can be a sign that you’re overwhelming your body with sugar. To boost your score, aim for hills, not mountains!
A step-by-step guide to calculating your Zone Score
Step 1. Start with a score of 10.
Step 2. Calculate deductions.
- If the value of the glucose peak is ≥ 100, the score changes according to the following formula:
- Glucose peak deduction = 1 – (maxGlucosePeak – 100) / 60
- By definition, if the value of the glucose peak is ≥ 160, the Zone Score will be 1
- If the slope of glucose change exceeds 2 mg/dL per minute, the score changes according to the following formula:
- Glucose slope deduction = 1 – (GlucoseSlope – 2) / 13
- By definition, if the slope of glucose change exceeds 15 mg/dL per minute, the Zone Score will be 1
- Similarly, if the area under the curve accumulates at > 5 mg/dL per minute, the score will change according to the following formula:
- Area under curve deduction = 1 – (AreaUnderCurve – 2) / 18
- By definition, if the area under the curve accumulates at ≥ 20 mg/dL per minute, the Zone Score will be 1.
Step 3. Take an average of values calculated in step 1 to generate a composite score.
Step 4. Round the composite score to the nearest integer and multiply it by 10 to generate a number between 1 and 10.
⭐ Note that our engineers are constantly working to improve app features, so the above may not precisely match the current zone scoring algorithm.
⭐ No score will be calculated if you do not have data sufficient to generate a baseline or during the 2 hours of the Zone.
Exceptions, notes, and caveats
The Zone Score is just one way of thinking about your glucose dynamics. If you prefer to stick to raw numbers instead of scores, you can look at your post-meal glucose levels, average glucose, or glucose standard deviation in the app.
Although we created our Zone Score formula from components of peer-reviewed studies on healthy glucose variability, the Zone Score is not yet a clinically validated tool.
On “megazones”
Note that a Zone will extend beyond two hours if you log an additional meal during this period. I.e., the clock effectively restarts with each log. For example, if you log bacon and eggs at 8:00 am, your Zone will end at 10:00 am. However, if you log Greek yogurt at 8:45 am, your Zone will extend until 10:45 am; if you also log a latte at 10:00 am, your Zone will extend until 12:00 pm, leaving you with a 4-hour Zone.
Indeed, if your logs are consistently under 2 hours apart, your day might look like one giant “megazone” rather than several shorter Zones. To avoid this, our Support team recommends logging multiple foods at once rather than creating separate entries. You can also edit your logs after the fact to consolidate logs.
“For instance, if you logged salad at 4:30 and then some almonds at 5:00, you can edit the logs so that there’s just one ‘Salad and Almonds’ entry at 4:45,” says Support expert Sunny Negless.
Exercise
The app won’t display a score for Zones with exercise alone because physical activity positively affects metabolic health (even if it causes a temporary spike in blood sugar). Be sure to log strenuous physical activity to avoid losing points for an exercise-related spike.
