In a ‘cruel twist’ for dangerously obese people, a new study has found that exercising with obesity reduces the number of calories burned while sitting still.
This means that for someone who is obese, losing weight through exercise will likely be significantly more difficult than for a lean person.
People who exercise burn fewer calories through “body maintenance” — the ongoing processes in the body that take place even when we’re completely at rest, experts say.
The point is that this unfortunate metabolic phenomenon has the most adverse effects on obese people.
Essentially, it means that obese people reduce their resting metabolism — the total number of calories burned when the body is completely at rest — the more active they are.
You may have to work extra hard to lose weight if you’re obese, a new study finds. This is because obese bodies are particularly good at retaining fat reserves
As a result, for every calorie they expend on exercise, they save about half a calorie on rest — a cruel twist for obese individuals.
The study was conducted by researchers from the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences and the University of Roehampton in London.
Study author Professor Lewis Halsey of the University of Roehampton explained bodywork maintenance, which he compared to a stationary car with the engine still running.
“In this state, the body is still burning energy for functions such as protein synthesis, the immune system, potassium-sodium pumps in our cells, kidney function, the beating of the heart, the brain’s thinking, ventilation,” he told MailOnline.
‘These functions do not only take place at rest, but the energy expenditure for body maintenance can be measured at rest, because by definition no other processes are taking place at that time.’
For the study, the team examined the effects of activity on energy expenditure and how these effects differ between individuals.
WHAT IS OBESITY?
Obesity is defined by your body mass index (BMI) – a measure of body fat based on your weight in relation to your height.
If you have a BMI of 30 or higher, you are obese. If it is between 25 and 29.9, you are overweight.
- BMI = (weight in pounds) / (height in inches x height in inches)) x 703
- BMI = (weight in kilograms / (height in meters x height in meters))
- Under 18.5: underweight
- 18.5 – 24.9: Healthy
- 25 – 29.9: overweight
- 30 or higher: obese
They conducted an analysis based on data from 1,750 adults in the IAEAs double labeled water database – a free-to-use collection of over 6,500 measurements of the daily energy consumption of people of all sizes living worldwide.
“When they participate in weight-loss exercise programs, most people lose some weight,” said study co-author Professor John Speakman of SIAT.
“Some people lose a lot, but a few unlucky ones gain weight.
‘This analysis with data from the DLW database shows that individuals are not all alike in the way they budget their energy consumption.
‘People with obesity can be particularly efficient at holding on to their fat reserves, making weight loss difficult.
Researchers found that the reduction in resting energy expenditure was most pronounced in obese individuals and also — to a lesser extent — in older adults.
In individuals with the highest body mass index (BMI), 51 percent of calories burned during activity translated into calories burned at the end of the day.
For those with a normal BMI, 72 percent of calories burned during activity was reflected in total expenditure.
Professor Halsey explains: ‘If you exercise on any given day and burn 300 kilocalories (kcal), you could expect to have burned a total of 300 kcal more by the end of that day than you would have burned otherwise.
In the long run, however, the body reduces the calories burned in other processes to partially compensate for the calories burned through activity.
‘So the 300 kcal burned during exercise doesn’t ‘translate’ to an extra 300 kcal that day, but maybe only 200 extra kcal that day, while 100 kcal less was burned on other processes to compensate.’
The observed discrepancy between people with a high and low BMI is probably due to so-called compensatory mechanisms.
Both obese people and the elderly have these compensatory mechanisms, researchers say.
These mechanisms include eating more food because exercise stimulates our appetite, or reducing our expenditure on other components such as our resting metabolism so that the exercise is actually less costly.
As a result, losing weight through more activity is likely to be significantly more difficult than for a lean person, whose compensation is much less and whose need to lose weight is much lower.
“Across the world, national guidelines recommend a calorie deficit of 500-600 through exercise and diet for weight loss,” says Professor Halsey.
Being overweight or obese leads to about 2.8 million deaths per year, according to the World Health Organization (WHO). Pictured, an obese woman
“However, they do not account for the reduction in the number of calories burned in the most basic human functions, as the body makes up for the calories burned during exercise.”
Recent studies have shown that 1.9 billion adults worldwide are overweight (with a BMI between 25 and 29.9) and 650 million are obese (with a BMI of 30 or more).
Being overweight or obese leads to about 2.8 million deaths per year, according to the World Health Organization (WHO).
It is estimated that by 2030 approximately 57 percent of the world’s adult population will be overweight or obese.
This new study is published in the journal Current Biology.
Obesity put a million people hospitalized in England last year
In England, a record one million people were hospitalized for obesity in 2020, official data shows.
Data released by NHS Digital shows that admissions for conditions caused by obesity or where obesity affected people’s treatment increased 17 percent from 2019 to 2020.
Women accounted for nearly two-thirds (64 percent) of hospital cases, and admissions were more common in poorer than affluent areas.
NHS England medical director Professor Stephen Powis called the numbers “shocking” and said they were “a growing sign of the country’s obesity crisis”.
He said obese people were at risk for cancer, heart disease and stroke and also put extra pressure on the NHS, which spends billions of pounds each year treating people for their weight.
People were most often hospitalized for arthritis in their hips and knees and for heart disease, while others required immediate treatment for their weight.
The NHS figures show that around 10,780 admissions were directly caused by obesity – for weight loss or stomach surgery – with the rest for problems related to obesity.
But in all, there were 1.02 million hospitalizations where someone’s obesity was cited as the main or secondary cause of their visit, up from 876,000 the year before.
The most common of these were for appointments during pregnancy, knee and hip arthritis, and heart disease.
Carrying extra pounds is not only a strain on your physical health, but also on the health service, so as lockdown restrictions begin to ease, there’s never been a better time to take steps to adopt a healthier lifestyle. lead,” said Professor Powis.