Obesity is recognised as one of the worst health epidemics worldwide, with 617,000 obesity-related admissions reported by the NHS in 2016/17.

Obesity can lead to health complications such as Type 2 Diabetes, coronary heart disease, stroke and certain types of cancer as well generally reducing quality of life.

A Growing Global Challenge

Worldwide obesity has nearly tripled since 1975. In 2016, more than 1.9 billion adults, 18 years and older, were overweight. Of these, over 650 million were obese.
World Health Organisation

These serious conditions can be life-threatening.

How can individuals and their health providers more effectively understand and treat the conditions associated with obesity?

Understanding the role of energy expenditure in controlling body weight is one crucial element.

Effective monitoring of an individual’s energy expenditure and caloric needs can help control and manage the health and wellbeing of the individual, reducing their likelihood of developing such conditions.

Harnessing the power of ECG biometrics is one exciting technological advancement that could do just that.

Understanding Energy Expenditure and Balance

Energy expenditure is a measurement used to determine the number of calories burned by an individual, including the caloric demands to carry out basic functions such as breathing, digestion and temperature regulation to increased caloric demands of physical exercise.




It is calculated by health professionals as the sum of the basal metabolic rate (the amount of energy expended while at complete rest), the thermic effect of food (TEF, the energy required to digest and absorb food) and the energy expended through deliberate and non-deliberate activity.

Energy balance refers to the difference between the number of calories consumed versus the number of calories expended, typically over the course of a day. Within this context, the terms energy and calories are used interchangeably with a calorie defined as “the energy required to raise the temperature of 1 kilogram of water through 1°C."

Put simply, if the number of calories consumed via dietary intake exceeds the number of calories the body requires to maintain it’s current body weight, including the additional calorie demands of physical activity, then an individual will gain bodyweight. Conversely, the opposite is true.

Energy balance is widely acknowledged as the most significant contributing factor to the global obesity crisis.

This makes understanding an individual’s energy balance key to managing the chronic conditions associated with obesity.

Monitoring Energy Expenditure: B-Secur Reports

Total energy expenditure is commonly comprised of four main components in humans: basal metabolic rate (BMR), thermic effect of food (TEF), non-exercise activity thermogenesis (NEAT) and the thermic effect of activity (TEA).

Arriving at a total involves a series of calculations, at least several of which will be based on approximations.

Using ECG biometrics could prove to be an integral part of understanding energy expenditure, with more personalised, detailed health data insights.

B-Secur’s HeartKey Energy Expenditure algorithm is one way we’re using ECG biometrics to help health providers access these insights.

ECG and Obesity

Adrian clarifies:

"It is important we test our algorithm against comparative devices and technologies to constantly evaluate HeartKey and ensure we remain proactive in the market."

"We want to determine the effectiveness of the technology to understand its utility in the health space by helping people to monitor their own health."

"With so many popular fad diets out there grabbing consumers attention and hard earned money, I feel it’s important people understand the critical role energy balance plays in any health and bodyweight related goal."


The data collection ran between a strictly enforced timeframe.

To ensure consistency across subjects, reliability in results and prevent the test subjects undergoing any unnecessary excess stress, the validation was conducted under controlled conditions.

During the study, each subject was required to complete an hourly activity log with a record of any physical activity as well as beginning and end times of each meal.

Exercise Protocol

The controlled exercise test for each subject was completed at a set time to maintain consistency between subjects.

Each subject completed a 10 minute cycle within an Aerobic Heart Rate Zone 2 to ensure energy demands were kept consistent relative to each subject.

This portion of the protocol was designed to validate the HeartKey Energy Expenditure algorithm during times of increased physical activity and thus increased heart rate (HR).

Each subject’s HR was monitored on the HeartKey app throughout the protocol by the test conductors.


The study validated the performance of the HeartKey Energy Expenditure algorithm against an energy expenditure algorithm of a commercially available device.

Comparing the performance of HeartKey algorithm and the commercial device, the importance of physiological metadata must be considered.

The commercial device showed that a a female test subject who was 30cm shorter and 40kg lighter than a male subject had a total energy expenditure of 3216kcal over 24 hours compared to a reported 1868kcals for the large individual . Conversely, the HeartKey algorithm reported 2236kcal and 2720kcal for the smaller and larger individuals, respectively.

Keeping in mind that test conditions including exercise were consistent across subjects it can be confidently stated that the commercial device is worryingly inaccurate across these two subjects when compared to the more realistic values the Heartkey algorithm reported.

Physiologically, the significantly smaller subject would almost always expend less calories within a controlled environment. Particularly when the magnitude of physiological difference is significant across gender, height and weight.

We were delighted to see the reliable performance of the HeartKey Energy Expenditure algorithm is further reinforced when considering BMR as a reliable basal rate of energy expenditure.

ECG Biometrics' Fight Against Obesity

Your energy output doesn’t have to exceed your input every day.

It's controlling your energy balance over time that will help you stay at a healthy weight over the long term.

Using an ECG signal coupled with meta data we can determine caloric needs per individual and controlling this (energy in vs energy out) over time can prevent obesity.

The data shows the existence of a very close relationship between the two variables demonstrating that continuous heart rate monitoring (ECG) may be considered as a valid tool for energy expenditure measurements.

To understand more about the possibilities of our algorithm, see our HeartKey information