Nutrino Explains: How We Really Calculate Your Breakdown

We can’t reiterate it enough – it’s so important to us that our recommendations and calculations in the Nutrino app are science based and personalized. One of our core values is that we don’t base our recommendations on counting calories. It’s what makes Nutrino Nutrino, and we’re really proud of that.

We also want you to know exactly where we’re getting these numbers and calculations from. So, in the name of transparency and science, here’s how we calculate your daily breakdown, step by step.

How do you calculate how many calories you recommend I eat each day?

The first thing Nutrino does is calculate your recommended daily calorie intake. In other words, your ‘range of energy to be consumed.’ To do so, we use the Harris-Benedict recommended intake determination, which is BMR * activity multiplier.

Ok, so what exactly is BMR?

Bare with me. BMR is the Basal Metabolic Rate, which is the amount of energy (calories) you need to keep your body functioning at rest.

How do we calculate BMR? We do it a bit differently than the original Harris-Benedict recommendation, as these formulas are proven to be a bit more accurate.  If you input your fat percentage, we can calculate BMR using the Mifflin St Jeor Equation:

mifflin eq


where LBM is the lean body mass in kg

If not, we use something called The Katch-McArdle Formula:

katch eq

where s is +5 for males and −161 for females.

Both of these formulas gives us the BMR to calculate your maximum recommended daily caloric intake. To get the minimum recommended daily caloric intake, we calculate 90% of your maximum recommendation.

Ok, so this is step one of calculating your recommended energy intake (calories). Step two is the activity multiplier. Remember, BMR is how much you need when your body is at rest. But what if you are a fitness guru who wakes up and runs marathons every morning? Or, more likely, you work out a few times a week. Or maybe you just walk to work and back. Whatever your activity level, the activity multiplier takes that into consideration.

Got it. So what is the activity multiplier?

Normally, when you ask for a recommendation for a certain day, we don’t have a complete picture of your day. Let’s say, for example, you plan your lunch on Monday. Later that night, you worked out, and we didn’t know that when you planned your lunch. This is why we use the activity multiplier to predict your activity levels. Remember, we don’t emphasize calorie counting, or calorie in/calorie out weight loss description. Rather, we believe that by using smart estimations and predictions we can holistically produce better recommendations that will help you achieve your goals.

How do you predict the activity multiplier if I’m not wearing a wearable activity tracker?

Okay, so how do we predict the activity multiplier? If we don’t have any dynamic data (such as data we collect from your wearable device like Fitbit), we use your activity level setting. This chart shows the activity multiplier for different activity levels, and how we calculate your total calorie intake recommendation.

Little to no exercise Daily kilocalories needed = BMR x 1.2
Light exercise (1–3 days per week) Daily kilocalories needed = BMR x 1.375
Moderate exercise (3–5 days per week) Daily kilocalories needed = BMR x 1.55
Heavy exercise (6–7 days per week) Daily kilocalories needed = BMR x 1.725
Very heavy exercise (twice per day, extra heavy workouts) Daily kilocalories needed = BMR x 1.9

I wear a Fitbit, or another wearable device. How do you use the data from my wearable device to predict the activity multiplier?

If you are a user who connects a wearable device that tracks movement and activities, Nutrino has data that we can use to assess your real, true, activity level. At the end of each day, we gather a summary of your movement and activity for that day, saving the total calories burned as detected by your device. We then subtract the BMR that the device uses from the total number of calories burned (as calculated by your device). This is because some devices calculate BMR slightly differently than we do, and we try to stay consistent in our calculations across all users.

We can now use the saved data from your device to predict your activity multiplier for the next day. Nutrino calculates the weighted average of your activity throughout the past week, giving a larger weight to the same day of the week we are evaluating. For example, if we’re predicting your activity level for the upcoming Tuesday, the previous Tuesday will be given more weight than other days in the past week.

You might think that this method would give inaccurate recommendations. Just because you worked out a certain amount one Tuesday doesn’t necessarily mean it’ll be the same the following Tuesday. Because we’re always adjusting next day constraints based on previous weeks, our calculations are dynamic. Examining activity over a longer stretch of days (rather than just one), actually gives a very strong closimty between the values. Even if you have a dynamic lifestyle in which you change your activity level regularly, Nutrino can stay up to date and provide you with accurate meal recommendations and daily breakdown.

In other words, look at your diet and calorie breakdown on a large scale. Zoom out for a second. Instead of looking at each activity individually, Nutrino’s calculations look at your lifestyle as a whole, giving you accurate meal recommendations and breakdowns.

Next step is to actually get an activity multiplier from this dynamic data. This part is simple for us: (Predicted Extra Exhaustive Calories + BMR) / BMR. The activity multiplier is always greater than one, and we put the upper limit at 2. Notice that the maximum activity multiplier when we don’t have dynamic data is 1.9.

Do you get any dynamic data from anywhere besides wearable devices?

Wearable devices, however, do not collect the only dynamic data that we can use. Let’s say, for example, you’ve connected Nutrino to your RunKeeper app, or approved Health Kit connection and allowed Nutrino to pull data from your Health App in real time. What if you are logging activities before they happen?

Don’t worry, we take care of that too. When Nutrino plans your meals for a specific day that already includes logged activities – whether fetched from Health Kit, notified by Runkeeper, or logged manually – we still calculate the activity multiplier by step 1 or 2. However, if the day’s logged activities give us a larger activity multiplier than what was predicted by step 1 or 2, Nutrino overrides that multiplier for the new, larger one.

Is there anything else I should know about how your recommendation technology works?

Of course, these constraints are not completely set in stone. While we believe in our calculations, we understand that at the end of the day many studies in nutrition are controversial and sometimes you need a breakdown that’s much more personalized. This is why we created the custom diet feature, where you can set your percentages of macronutrients protein, fat, and carbs. You can also set your caloric intake, as well as sodium and fiber levels. We let you choose wha you believe is right for your body.

We also understand that sometimes the rules have to be stretched just a little. In the case that no meal recommendation falls within your parameters, we relax the constraints (just a little bit) and try again – getting you the best possible recommendation to help you meet your goals.

We also adjust our recommendations if you set goals – like lose or gain weight, reduce fat percentage, or gain muscle mass. An explanation on these adjustments is coming soon.

Really cool. Now I know how you calculate my daily calorie intake. How do you calculate the percentage of each nutrient I should be eating?

Of course, we don’t only calculate your total recommended calorie intake. A healthy diet must provide the body with essential nutrients (macronutrients including all essential amino acids, essential fatty acids, vitamins, minerals, and sufficient calories to maintain proper cell functionality). Nutrino’s guidelines are compatible with the USDA, the NHS, the World Health Organization, and the major leading nutrition schools in the world (e.g. the Harvard School of Public Health). Here’s how we accurately calculate some other important nutritional information:

Total Fat: After calculating your max calorie intake range, we calculate your total fat constraint by ensuring you get 20-35% of your calories from fatty acids
Total Protein: Nutrino ensures you get 10-35% of your calories from protein
Total Carbs: Nutrino ensures you get 45-65% of your daily calories from carbs
Dietary Fiber: Dietary fiber intake varies based on gender and age. For men age 14-50, Nutrino recommends 38 g of daily dietary fiber, and for men 51 and older, 31 grams. For women age 18-50, Nutrino recommends 25 g of daily dietary fiber, and for women 51 older, 21 grams.
Sodium: Nutrino recommends 500-2000 mg of sodium
Saturated fat: Nutrino’s recommendations minimize saturated fat; to 0% if possible, but never more than 10%.

This is how we give you the best recommendation possible that is tailored to meet your specific needs. Unlike other health and diet apps, there are no pre made or one-size meal plans. Each meal is chosen specifically for you, based on your specific needs at that time. If you have more questions about how this works, send us an email, or reach out on Facebook or Twitter. Download Nutrino to see what meals are best for you.