Keeping tabs on daily calories, nutrients, and activity is a way of life for many who swear it is an invaluable crutch for helping them shape up.

Statistics from Sport Ireland suggest that, even in 2021, more than half the population uses wearable technology to track their physical activities, although with the boom in tracking — global downloads of diet and fitness apps grew to 3.6bn worldwide last year — it is likely there has been another sizeable leap in their use since then. Apps and trackers are intended to guide us along the path to wellness, but research suggests that the outcomes of relying too heavily on advice from a diet or fitness app can be life-changing for all the wrong reasons.

Paulina Bondaronek, a research fellow in behavioural science at University College London, has been investigating health apps for most of the past decade. Her latest study looked at 58,881 posts on social media relating to five of the popular health and fitness apps.

Many users expressed disappointment and anxiety at their slow progress towards algorithm-generated targets, felt “pestered” by app notifications, and said that the difficulty of sticking to rigid goals quickly led to loss of motivation. For some, this led to them quitting, defeating their intended purpose. Others developed feelings of failure and self-loathing that might exacerbate low body image.

It follows a review of 38 studies earlier last year in which researchers at Flinders University in Australia raised concern about growing numbers of diet app users becoming obsessed with targets to the point of developing disordered eating habits.

“The focus on dietary restriction and weight loss in these apps may feed into restrictive or excessive behaviours, raising concerns for those people who have pre-existing concerns about their weight or body image,” says Isabella Anderberg, a researcher in the College of Education, Psychology, and Social Work, who led the study.

Finding the fitness data overload stressful? Here’s how to use it to maximise your progress:

Take the data with a pinch of salt

“Many health apps are still based on very crude metrics, which is concerning,” says Bondaronek. Picture: iStock“Many health apps are still based on very crude metrics, which is concerning,” says Bondaronek. Picture: iStock

“Many health apps are still based on very crude metrics, which is concerning,” says Bondaronek.

“Nearly all of them start by asking your height, weight, and how much weight you want to lose with no health professionals involved in determining whether this is an appropriate goal.”

Algorithms have become more sophisticated in recent years, especially with the use of AI interpretation of data, but, they still lack “the personalisation and tailoring needed to be fully accurate”.

Most diet-tracking apps aren’t 100% precise and come with a significant margin of error.

A systematic review and meta-analysis published in Advances in Nutrition found that mobile dietary record apps often under- or over-estimate energy, macronutrient and micronutrient intake.

That team of researchers from the Netherlands reported “large variability among apps” in real-life settings, so use them as rough guides, not gospel.

Use apps that encourage group work

There is strong evidence that working out with others for moral support is the best way to stick with your fitness goals.There is strong evidence that working out with others for moral support is the best way to stick with your fitness goals.

Sports psychologist Dearbhla McCullough says there is strong evidence that working out with others for moral support is the best way to stick with your fitness goals.

“Social connectedness and even feeding back to others are so important in creating fitness habits that stick,” McCullough says.

Likewise, fitness apps that encourage interaction are often more effective than those that require users to complete tasks, such as daily steps, on their own.

“Self-monitoring and action planning are powerful behaviour change techniques,” says Bondaronek.

“But we can over-use data tracking apps [that encourage solo workouts] to the point where they become detrimental.”

Don’t become obsessed with macronutrient tracking

There’s no evidence that macronutrient tracking offers greater long-term weight-loss benefits than calorie counting or other diet approaches. Picture: iStockThere’s no evidence that macronutrient tracking offers greater long-term weight-loss benefits than calorie counting or other diet approaches. Picture: iStock

Some apps push tracking macronutrients — fat, carbs, and protein — rather than calories as a healthier route to weight loss with recommendations to increase the proportion of satiating protein to carbs. But Bondaronek found that this also led to unhealthy obsessions for many.

“When people started thinking just in terms of the fat and protein in their food, it became all-consuming,” she says. “The difficulty of sticking to rigid goals led to loss of motivation.”

There’s no evidence that macronutrient tracking offers greater long-term weight-loss benefits than calorie counting or other diet approaches.

A review of 14 popular diets in the British Medical Journal found that “most macronutrient diets, over six months, resulted in modest weight loss” but that the effects on weight loss “largely disappeared” after a year.

Fertility and ovulation tracking apps are prone to inaccuracy

The scientific validity of some fertility apps has been called into question. Picture: iStockThe scientific validity of some fertility apps has been called into question. Picture: iStock

Bondaronek’s next study focuses on the vast market for menstrual-tracking apps used by millions of women to log energy levels, symptoms such as cramps and cravings, and to track ovulation and fertility.

Most tracking apps work by women entering the date of their period, and a calendar-based algorithm predicts the start date of their next period, initially based on a 28-day cycle but using patterns and trends to learn about the user as they enter more information.

Some apps offer the option to add biometric data, such as daily body temperature, cervical mucus consistency, or hormone levels in urine.

However, Kirsty Elliot-Sale, a professor of female endocrinology and exercise physiology at Manchester Metropolitan University, says they are pointless.

“If you use a urine test to predict ovulation, then you know when you are ovulating and don’t need to pay for an app on top,” she says.

“The app is just a way to house the data you get from these tests.”

The scientific validity of some fertility apps has been called into question. Researchers have shown that apps promising to predict a user’s ovulation date, usually 14 days after their period starts, “have been proven to be ineffective, with a 21% maximum probability of it being correct”.

Sleep trackers might not help you sleep

For some, obsessing over the data leads to an unhealthy preoccupation with hitting sleep targetsFor some, obsessing over the data leads to an unhealthy preoccupation with hitting sleep targets

Sleep trackers mostly use sound, heart rate, and movement to estimate sleep phases and to provide a score.

For some, obsessing over the data leads to an unhealthy preoccupation with hitting sleep targets that has been dubbed orthosomnia. Ironically, it can lead to anxiety that makes sleep patterns worse, not better. Most sleep trackers provide feedback on how well — or not — you have slept, which is often evident anyway by how tired you are feeling when you wake up.

“It is sometimes a good idea to self-evaluate your sleep without relying on a tracker, even if it is just for a few days each month,” says McCullough.

“Really get to know your own sleep patterns and what works — or doesn’t — for you.”