How Smart Devices and Wearables Are Shaping Weight Management
Can the Internet of Things (IoT) help with weight management, or is it just another tech trend? From fitness trackers to AI-powered food logging, digital tools are making it easier to monitor diet and exercise. But are they truly effective in achieving long-term health goals?
The internet of things – what? The internet of things is the network of internet-connected devices, such as tablets, cell phones, and fitness trackers, that can exchange information.[1] These devices have become tools for managing health and body weight.[2] Over 40% of Americans adults use health-related cell phone apps and 35% use wearable trackers to monitor the key components of weight management – how much we eat and how much we move.[3] Does using this internet of things help people to manage their weight or is it just another gimmick?
Managing Body Weight
Managing body weight requires balancing the calories we eat with the calories we expend in physical activity in order to bring our weight into the healthy range and keep it there. Currently, Americans are not doing a very good job of this; forty percent of U.S. adults are obese. [4] The typical American diet contains too many high-calorie, highly processed foods and sugar-sweetened beverages, and not enough fruits and vegetables; less then 25% of adults meet physical activity recommendations.[5,6] Managing weight requires choosing a healthier diet and getting more exercise. However, these lifestyle changes are difficult to make and even more challenging to maintain. An important component of successful behavior change is monitoring intake and/or activity.[1] The internet of things offers a variety of tools that assist in self-monitoring.
Digital Tracking of Activity and Intake
We typically track activity using “wearables,” which are electronic devices worn on the body to capture and relay medical, biological, and exercise data.[7] While early wearable trackers counted steps to monitor activity, newer devices actually estimate how many calories we expend. Calorie expenditure is measured using a combination of sensors. Some measure movement and acceleration to track the amount of activity, while sensors that monitor heart rate assess the intensity of activity. This data is interpreted using complex algorithms that estimate the number of calories burned. Devices such as Apple watches, Fitbits, Samsung rings, and Garmin fitness trackers can now tell you how many calories you have burned in a specific workout such as an outdoor run, a bicycle ride, or a pool swim, as well as for the entire day.
The ability to track calorie intake currently requires more effort than merely strapping on a wearable. The old school way to monitor intake is to record everything you eat and drink and then calculate your calorie intake from this log, but this can be tedious and time consuming. The process has been made easier by nutrition and fitness apps that instantly calculate the calories in each food you record and keep a tally of calories for the day.[8] But to use these, you still need to log the food on your device and measure or estimate the portions you consume. To make this easier, there are apps that upload nutrition data for packaged foods when you scan the barcode on the label; a downside is that this information is only reliable if you consume the portion size listed on the label. Other apps use AI to estimate portions and calculate calories from a photo of your plate of food; this can also simplify tracking, but these apps only have data for a limited number of foods.[9]
The latest technology for tracking intake, much of which is still under development, assesses consumption by monitoring eating behaviors and physiological changes. Some use sensors and cameras to measure how many times you chew or move your hand to your mouth.[10] Another wearable estimates calorie consumption using a sensor that measures the movement of nutrients and fluids in and out of cells.[11] While this technology reduces the burden of recording intake, it can’t estimate calorie intake until nutrients are absorbed, which can take up to 8 hours after eating. This limits the usefulness of tracking for people who rely on real-time calorie data to modify their intake throughout the day.
A drawback of trackers is that the data these devices generate are not necessarily accurate. For example, the number of steps your tracker records may vary depending on the type of activity you are engaged in and whether you wear the tracker on your wrist, ankle, or hip.[12] Tracking calories expended in activity is even less accurate than step counting. A review of the literature found that none of the devices evaluated were within 30% of actual energy expenditure.[12] Accurately tracking food intake is also fraught with problems; consumers may forget to log all of their intake or misjudge their portions sizes. [1,13] These inaccuracies can reduce the effectiveness of tracking for weight loss, particularly if you follow the numbers precisely. For example, if your tracker overestimates the calories you burn or you underestimate your portions, you may allow yourself to consume more, eventually stalling your weight loss.
Can the Internet of Things Help You Lose Weight?
The internet of things facilitates self-monitoring, which can help improve exercise and dietary patterns.[1] A review of the effectiveness of activity trackers found that users increased their physical activity and overall fitness.[14] Likewise, people who track their food intake are more likely to succeed at losing weight. [15] Logging what you eat can make you more aware of what and how much you eat; this increased awareness makes you more accountable for your choices and help you to monitor your progress.
Currently, millions of Americans are using fitness trackers to promote physical activity and weight loss, but long-term success is dependent on continuing to track and about a third of users stop tracking within a few months. [16,17 Some tracker attrition is related to ease of use; less tech-savvy users may quickly give up their devices if they can’t comfortably interact with them.[18] Some users have specific tracking objectives, so they are more likely to continue to track if they can set these as goals in their trackers.[19] Others rely on the goals and motivators programmed into trackers. Reminders telling users to “stand up” or that they have exceeded calorie limits can be encouraging to some but annoying to others. Some tracking apps try to increase motivation and continued use by offering virtual rewards for achieving specific milestones and incorporating the ability to compete with others and participate in online communities. For continued success, the tracking technology needs to match the needs of the user. When users are engaged and motivated either on their own or through their devices, they are more likely to continue tracker use and when they continue to track, they are more likely to succeed. [1,19]
Bottom Line
Monitoring what you eat and how active you are is important for successful weight management. When individuals are aware of what and how much they eat, they are more likely to make healthy choices and when they track their exercise, they are more likely to challenge themselves to do more.[20] Although not the solution for everyone, tracking, through the internet of things, allows users to conveniently monitor activity and intake. For those who continue to use it in the long term, it is more than just a gimmick, it is a valuable tool for managing body weight.
References
[1] Del-Valle-Soto C, López-Pimentel JC, Vázquez-Castillo J, et al. A Comprehensive Review of Behavior Change Techniques in Wearables and IoT: Implications for Health and Well-Being. Sensors. 2024;24(8):2429. doi:https://doi.org/10.3390/s24082429
[2] Tricás-Vidal HJ, Lucha-López MO, Hidalgo-García C, Vidal-Peracho MC, Monti-Ballano S, Tricás-Moreno JM. Health Habits and Wearable Activity Tracker Devices: Analytical Cross-Sectional Study. Sensors. 2022;22(8):2960. doi:https://doi.org/10.3390/s22082960
[3] Vaidya A. Over a Third of Adults Use Health Apps, Wearables in 2023, Up From 2018. Virtual Healthcare. Published 2023. https://www.techtarget.com/virtualhealthcare/news/366597158/Over-a-Third-of-Adults-Use-Health-Apps-Wearables-in-2023-Up-From-2018
[4] CDC. FastStats - Overweight Prevalence. Centers for Disease Control and Prevention. Published January 5, 2023. https://www.cdc.gov/nchs/fastats/obesity-overweight.htm
[5] CDC. Healthy Habits: Fruits and Vegetables to Manage Weight. Healthy Weight and Growth. Published May 8, 2024. https://www.cdc.gov/healthy-weight-growth/healthy-eating/fruits-vegetables.html
[6] CDC. FastStats - exercise or physical activity. CDC. Published December 15, 2022. https://www.cdc.gov/nchs/fastats/exercise.htm
[7] Yasar K. What is wearable technology? - Definition from WhatIs.com. SearchMobileComputing. Published May 2022. https://www.techtarget.com/searchmobilecomputing/definition/wearable-technology
[8] Van Pelt J., Performance Nutrition and Wearable Trackers - Today’s Dietitian Magazine. www.todaysdietitian.com. https://www.todaysdietitian.com/enewsletter/enews_0421_01.shtml
[9] Hill S. Photograph your meal with the Foodvisor app for caloric, nutritional estimates. Digital Trends. Published January 22, 2019. https://www.digitaltrends.com/mobile/foodvisor-calorie-counting-app/#dt-heading-just-snap-a-pic
[10] Alshurafa N, Lin AW, Zhu F, et al. Counting Bites With Bits: Expert Workshop Addressing Calorie and Macronutrient Intake Monitoring. Journal of Medical Internet Research. 2019;21(12):e14904. doi:https://doi.org/10.2196/14904
[11] HealBe. GoBe Features. How Does GoBe Measure Calorie Intake?
Healbe.com. Published 2023. Accessed February 19, 2025. https://healbe.com/info_intake_gobe3
[12] Germini F, Noronha N, Borg Debono V, et al. Accuracy and Acceptability of Wrist-Wearable Activity-Tracking Devices: Systematic Review of the Literature. Journal of Medical Internet Research. 2022;24(1):e30791. doi:https://doi.org/10.2196/30791
[13] Bailey RL. Overview of Dietary Assessment Methods for Measuring Intakes of foods, beverages, and Dietary Supplements in Research Studies. Current Opinion in Biotechnology. 2021;70(PMC8338737):91-96. doi:https://doi.org/10.1016/j.copbio.2021.02.007
[14] Patel MS, Asch DA, Volpp KG. Wearable Devices as Facilitators, Not Drivers, of Health Behavior Change. JAMA. 2015;313(5):459. doi:https://doi.org/10.1001/jama.2014.14781
[15] Ferguson T, Olds T, Curtis R, et al. Effectiveness of wearable activity trackers to increase physical activity and improve health: a systematic review of systematic reviews and meta-analyses. The Lancet Digital Health. 2022;4(8):e615-e626. doi:https://doi.org/10.1016/s2589-7500(22)00111-x
[16] USDA NUTRITION EVIDENCE LIBRARY Diet Self-Monitoring and Body Weight: A Review of the Evidence Nutrition Insight 48 BACKGROUND.; 2012. https://nesr.usda.gov/sites/default/files/2019-05/Diet%20Self-Monitoring%20and%20Body%20Weight.pdf
[17] Fawcett E, Van Velthoven MH, Meinert E. Long-term weight management using wearable technology in overweight and obese adults: A systematic review (Preprint). JMIR mHealth and uHealth. 2020;8(3). doi:https://doi.org/10.2196/13461
[18] Attig C, Franke T. Abandonment of personal quantification: A review and empirical study investigating reasons for wearable activity tracking attrition. Computers in Human Behavior. 2020;102:223-237. doi:https://doi.org/10.1016/j.chb.2019.08.025
[19] Jin D, Halvari H, Maehle N, Olafsen AH. Self-tracking behaviour in physical activity: a systematic review of drivers and outcomes of fitness tracking. Behaviour & Information Technology. 2020;41(2):1-20. doi:https://doi.org/10.1080/0144929x.2020.1801840
[20] Georgia State University. Are Fitness Watches Motivating Users to Stick to Fitness Goals? Here’s What the Research Says. Georgia State News Hub. Published January 23, 2024. Accessed February 19, 2025. https://news.gsu.edu/2024/01/22/fitness-watches
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