Track Weight with the iPhone

How do you track weight with the iPhone?

Do you want to lose weight? Or, perhaps you want to bulk up your muscles? If you answered yes to either of these questions, then you will want to track your weight and body composition with your iPhone. This blog post is the first in a two-part series. In this first post, we will cover tracking your body weight. The second blog post will cover how to track body composition with the iPhone.

Using the Health App to Track Weight

The Health App stores your height and weight, your BMI, your gender and age. When you first ran the Health App you may have entered your height and weight. It is likely that you have not updated your height and weight since then.

Here’s how to manually enter your height and weight into the Health app:

Enter your weight

1. Weigh yourself on any scale
2. Run the Health app on your iPhone
3. Tap Health Data (at the bottom of the screen)
4. Tap Body Measurements
5. Tap the orange box marked Weight
6. On the Weight screen tap on the + in the upper right corner
7. Enter your weight
8. Tap Add in the upper right corner

Enter your height

1. Measure your height
2. Run the Health app on your iPhone
3. Tap Health Data (at the bottom of the screen)
4. Tap Body Measurements
5. Tap the orange box marked Height
6. On the Height screen tap on the + in the upper right corner
7. Enter your height
8. Tap Add in the upper right corner

What is BMI?

BMI, which stands for Body Mass Index, is a calculation based on a person’s height and weight that is used to determine whether or not a person is at a healthy weight. A person’s BMI is their weight in kilograms (kg) divided by their height in meters squared.

To calculate your BMI by using pounds and inches, divide your weight in pounds by your height in inches squared; then multiply by 703. For example, a 140-pound, 5-foot-6-inch person has a BMI of 22.6 (140 divided by 66, divided by 66, times 703).

Here is an online BMI calculator
Here is a free BMI app

The National Institutes of Health (NIH) defines normal weight, overweight, and obesity according to BMI rather than the traditional height/weight charts. If a person’s BMI is over 25 then they are is considered overweight.

The limitation of BMI that may be misleading is that it measures excess weight rather than excess body fat. It does not take into account factors such as muscle mass and body fat percentage. Athletes or people who have a muscular build may have a BMI that indicates that they are overweight or even obese. On the other hand, older persons and others who have lost muscle, may have a BMI that is normal even though they may have excess body fat.

Nonetheless, since BMI is so easy to track and can provide an indication of whether you are overweight or not, it is a good measurement to track as you start losing weight.

Track your BMI in the Health App:

1. Run the Health app on your iPhone
2. Tap Health Data (at the bottom of the screen)
3. Tap Body Measurements
4. Tap the orange box marked Body Mass Index
5. On the Body Mass Index screen, tap on the + in the upper right corner. The BMI is automatically calculated from your latest height and weight entries.
6. Tap on Add in the upper right corner

So, how do I track weight over time?

You can continue manually entering your weight into the Health App every day, or once a week and then view it on a weekly or monthly graph. The problem is that inputting your weight into the Health App daily can become tedious. One way to simplify the process is to set up a Shortcut to log your weight each day.

In iOS 12, Apple has added the Shortcuts app. While this app is part of iOS 12, it is not installed automatically.

Here are the steps to install the Shortcuts app:

1. On your iPhone: View the Shortcuts app in the App Store
2. Install the Shortcuts app by tapping Get
3. Run the Shortcuts app by tapping Open
4. Tap on Get Started

We have created our own shortcut called Log Weight & BMI. This shortcut enables you to tell Siri: “Log my weight” which will run the shortcut. You will be asked to enter your weight. Your BMI is automatically calculated and then your weight and BMI are saved into the Health App for easy tracking.

Here are the steps to install the Log Weight & BMI Shortcut:

1. Install either of these shortcuts depending on whether you prefer pounds or kilograms:
   Log Weight & BMI (Lbs)
   Log Weight & BMI (Kg)
2. Tap on Get Shortcut
3. Tap on Library (at the bottom left)
4. Tap on the shortcut, Log Weight & BMI
5. You may be asked to allow Shortcuts to access to your Health data. If you are asked, tap on Turn All Categories On, then tap Allow
6. Follow the shortcut’s instructions

How to run this shortcut with voice activation:

1. Tap on the three dots in the upper right of the Log Weight & BMI shortcut
2. Tap on upper right switches icon that opens the Settings Screen
3. Tap on Add to Siri
4. Tap the red record button at the bottom of the screen and record the phrase you would like to use to activate this shortcut. We recommend “Log my weight”.

Track weight using 3rd Party Apps

Another way to simplify the process of tracking your weight daily is by using 3rd party weight tracking apps on your iPhone.

There are many apps that help you track your weight. You still need to enter your weight manually, but these apps simplify things by recording your weight and saving the information into the Health App. You will be able to view a graph of your progress.

An example of two good 3rd party weight tracking apps:

1. Happy Scale (free, offers in-app purchases, premium version costs $4.99) calls itself a “Predictive Weight Loss Tracker.” This app has a clear, easy to use interface. Users can set weight loss goals that can be broken down into small, incremental steps. This enables the user to focus on short-term, achievable goals. Happy Scale uses mathematical analysis to track your true progress and enables prediction of what your weight will be for an upcoming event. The premium version of Happy Scale ($4.99) integrates with Apple Health and other weight tracking apps.
2. Weight Drop (free, offers in-app purchases, premium version costs $0.99) is a simple weight tracker with a single screen overview of all of your weight information. Easily record your weight once a day without any additional calorie counters or diet diaries to defocus you from the task of weight tracking.The premium version of Weight Drop eliminates ads, can calculate BMI, provides weights stats and includes CSV import/export so that you can use the data in a spreadsheet and send the data to your healthcare provider. Weight Drop doesn’t have the “predictive ability” that Happy Scale has which may make it simpler to use if you don’t want this added feature.