Anybody who has grappled with weight loss knows that even once the kilos come off, it can be hard to keep them off in the long term.
A study on the hormones that govern feelings of hunger and fullness has shown why it’s such a struggle for some individuals, revealing that changes in body chemistry two years after shedding weight can have an impact on our desire to go back for second helpings.
Researchers from Norway and Denmark made the discovery after tracking the fitness, body mass index (BMI), hormone concentrations, and reported hunger levels of 35 adults over two years.
Each volunteer entered the program as severely obese before undergoing a rigorous weight loss program involving a calorie-restricted diet, exercise, and therapy.
Following a three week residential session, the participants went home and continued to exercise and eat healthier.
Two years later all of the subjects successfully lost significant amounts of weight and had better cardiovascular fitness. But their hormones and reported feelings of fullness and hunger told an interesting story.
A month into the weight loss program, the volunteers reported feeling fuller after meals, and experienced no significant change in their hunger levels while they fasted.
Coinciding with this sensation were higher levels of a hormone called peptide YY, which when released in the gut shuts down appetite and impedes our gastric functions.
All good news.
But one year later, those feelings of fullness went south as hunger levels and a desire to eat steadily climbed. Worse still, they remained high after another twelve months.
These hunger sensations were reflected in their levels of a hormone called ghrelin, which slowly crept up from day one.
Meanwhile those appetite-satisfying peptide YY levels stayed steady after the four week mark, not shrinking but not climbing any higher either.
In other words, their initial efforts in improving activity and changing diet were rewarded with a depressed appetite, but pangs of hunger quickly took over any sensations of a satisfied belly.
The study can’t tell us much about the exact mechanisms behind these hormone changes, and the researchers admit in their report that they don’t have enough information to comment on the energy balance of the participants at the time measurements were taken.
Knowing details about the metabolisms of those losing weight might help us better understand what’s going on below the surface.
But the research does show how losing weight isn’t always a simple case of setting up good habits and watching the fat fade.
For many in the overweight and obese category who want to lose weight, it’s not enough to just muster the willpower to get up more often and eat smaller, healthier portions.
We are only just beginning to understand the effects weight gain has on how we store fat, and the difficulties involved in reversing the impact of being obese in the first place.
Research like this shows how complex weight loss can be, while also providing hope that with such knowledge there could be solutions that might just make it easier in the future.
This research was published in American Journal of Physiology-Endocrinology and Metabolism.
Artificially-sweetened beverages (ASBs) are marketed as a healthy alternative to sugar-sweetened beverages (SSBs), but a paper compiled by scientists from Imperial College London and two universities in Brazil states that there is no proof that diet drinks are healthier or help in weight loss.
“A common perception, which may be influenced by industry marketing, is that because ‘diet’ drinks have no sugar they must be healthier and aid weight loss when used as a substitute for full-sugar versions. However, we found no solid evidence to support this,” Professor Christopher Millett, top researcher at Imperial’s School of Public Health, said.
In fact, there are mixed scientific findings on the matter, the study says.
“The effect of ASBs on weight management has been tested in some randomized controlled trials (RCTs). These have produced mixed findings, with some studies indicating a null effect, while others have found modest reductions in weight.”
Diet drinks can contribute to the problem, as “characteristics related to ASB composition (low nutrient density and food additives), consumption patterns (potential promotion of sweet taste preference), and environmental impact (misuse of natural resources, pollution, or ecotoxicity) make them a potential risk factor for highly prevalent chronic diseases,” the study adds.
Sugar-free drinks now constitute about a quarter of the global soft drink market, according to an Imperial College London press release.
In 2015, the World Health Organization recommended adults and children reduce their daily intake of free sugars to less than ten percent of their total energy intake, triggering the introduction of measures in some countries to reduce the consumption of drinks with added sugar.
As a result, ASBs have emerged as an important alternative to maintain beverages companies’ profits.
The study’s co-author, Carlos Monteiro, believes that taxes and regulations on SSBs and not ASBs will help promote the intake of diet drinks “rather than plain water, the desirable source of hydration for everyone.”
Not everyone agrees with the study’s claims, however. The head of the British Soft Drinks Association, Gavin Partington, told The Guardian that “scientific research shows that low-calorie sweeteners, such as those found in diet drinks, help consumers manage their weight as part of a calorie-controlled diet.”
Low fat diets and exercise are pointless for those wanting to lose weight and obese people should simply eat less, a former shadow health minister told the House of Lords yesterday.
Lord McColl, emeritus professor of surgery at Guys Hospital in London, warned that current health advice to avoid fat was ‘false and misleading’ and was fuelling the obesity epidemic.
Speaking at a House of Lords debate, the former surgeon warned that exercising was useless against the huge levels of calories from carbohydrates and sugars that people are now consuming. He warned that the obesity epidemic was as bad for public health as the 1919 flu epidemic.
“In the UK the Department of Health and Nice (National Institute for Health and Care Excellence) maintains for many years that the obesity epidemic was due to lack of exercise,” he told peers.
“It’s a pity that the 500 people employed by Nice didn’t think to go into the gymnasium get on a machine and exercise to see how few calories you actually burn off.
“One can pedal away on one of those machines for half an hour and only two or three hundred calories are burned up. One has to run miles to take a pound of fat off.
“The whole subject has been bedevilled by all sorts of theories about the course of the obesity; genetics, epigenetic, psychological disturbances. None of them is the cause of the obesity epidemic.
“One fact remains. It is impossible to be obese unless one is eating too many calories.”
In May the National Obesity Forum and the Public Health Collaboration called for a major overhaul of dietary guidelines saying 30 years of urging people to adopt low-fat diets was having ‘disastrous health consequences.’
Their report claimed the low-fat and low-cholesterol message, which has been official policy in the UK since 1983, was based on “flawed science” and had resulted in an increased consumption of junk food and carbohydrates.
Lord McColl said eating fat was important because it kept people feeling fuller for longer, and advised overweight people to start adding fat into their diet.
“Fat enters the small intestine and greatly delays the emptying of the stomach,” he told peers.
“As the stomach emptying is delayed it gives the feeling that one has had enough to eat. Later when the fat has been absorbed the stomach then starts to empty again, It’s a beautifully balance mechanism which tends to prevent us from eating too much and prevents us from getting obese.”
Researchers at Imperial College recently found that Britons are on course to be the fattest in Europe within a decade, with almost four in 10 people predicted to be dangerously overweight by 2025.
Earlier this week, Sir Simon Stevens the chief executive of the NHS said the obesity crisis was now costing more than the police and fire brigade combined.
“Obesity and its related illness is costing the country a fortune and it is not sustainable,” said Baroness Jenkin who called the debate in the Lords.
“If we don’t wake up to the extent of this crisis the NHS could end up bankrupt. Already enormous amounts of money are spent on disease which are entirely preventable
“The current dietary advice is confusing. The ‘Eat Well guide recommends potatoes, rice, pasta and other starchy carbs. Are we so sure that is good advice? We feed starchy crops to fatten animals so why would they not have the same effect on us?”
Health minister Baroness Chisholm said: “There is no point going to an exercise class or a gym then going around the corner for a fizzy drink a donut. It is this sort of culture that needs to change.
“Tackling obesity is an important issue. Obesity is a complex issue to which there is no single solution.
“I would like to underline that Public Health England bases it dietary guidelines on comprehensive reviews. They consultant with academics, health charities and public health professionals.”
Post birth, many woman desire to return to their pre-pregnancy size weight. This infographic provides tips and information to enable young mothers to achieve their goal. Dieting is not really the way to do it but following these guidelines will certainly help. A combination of healthy diet plus some exercise will help to lose weight after having a baby.