obesity

Posted on Mental health

Genetic links between depression and obesity explored

Obesity - an overview

Obesity – an overview

“Genetic variants linked to high BMI can lead to mental health issues,” reports The Guardian.

Depression is more common among people who are obese. But previous studies have not been able to determine whether there is a direct cause and effect relationship. So it could be the case that depression causes weight gain rather than the other way around, or indeed both could be true.

Also, it could be the complications associated with obesity, such as type 2 diabetes, are contributing to depression rather than the obesity itself.

This latest study attempted to use a genetic technique to focus on the direct effect of obesity on depression, removing the effect of other lifestyle and health factors. The researchers looked at the DNA of around half a million adults with white European ancestry in the UK.

The researchers looked at 73 genetic variations which had previously been linked to higher BMI. Some of these had also been linked to a reduction in risk of metabolic complications such as high cholesterol or blood sugar levels, rather than the increase that might be expected.

The researchers found that having a combination of the genetic variants which were associated with higher BMI was also associated with depression. This was some evidence that it was even the case when a person had the variants which reduced their risk of metabolic complications. This may suggest that obesity influences depression risk through psychological rather than metabolic changes; at least in some cases.

While we cannot change our DNA, taking regular exercise and eating healthily can help people achieve or maintain a healthy weight, and also help people with depression. Read more about how exercise can boost your mood and improve your health.

Where did the story come from?
The study was carried out by researchers from The University of Exeter Medical School, the University of South Australia Cancer Research Institute and King’s College London.

The researchers were funded by the Diabetes Research and Wellness Foundation, the Australian Research Training Program, the UK Medical Research Council, the Wellcome Trust, the European Research Council, the Royal Society, the Gillings Family Foundation, Diabetes UK, the National Institute for Health Research (NIHR) Biomedical Research Centre, Maudsley NHS Foundation Trust and King’s College London. The study was published in the peer-reviewed International Journal of Epidemiology on an open access basis so it is free to read online.

The Guardian reported the study accurately, including a mention of the limitations. The Mail Online provided sketchy details of the study, skirting over any of the genetic analysis and concluding that the psychological impact of being overweight increases the risk of depression, when this was only suggested by the results and not proven.

What kind of research was this?
This was a case-control study, comparing the genetic makeup of people with and without depression.

Depression is more common among people who are obese. However, it is not known whether obesity can directly increase a person’s risk of depression, whether the reverse is true, or both are true.

So researchers carried out a particular type of case-control study known as a Mendelian randomisation study, where researchers focused on genes known to be associated with disease risk and health outcomes rather than lifestyle factors.

The idea behind this type of study is the exact combination of DNA that people inherit from their parents is random. So the analysis reduces the possibility that other factors (confounders) are causing the links seen between obesity and depression.

What did the research involve?
The researchers used genetic information from about 450,000 UK adults with white European ancestry who had volunteered to be part of the UK Biobank, and have their DNA studied for research purposes.

The researchers identified 48,791 people with depression and 291,995 people without depression (controls) whose BMI had been measured, and compared their DNA.

People were identified as having had depression based on having reported either:

that they had seen a GP or psychiatrist for nerves, anxiety, or depression and experienced at least 2 weeks where they felt depressed or unenthusiastic
UK national hospital records indicated that they had a diagnosis of recurrent major depressive disorder (MDD) or single-episode MDD
The researchers also looked at whether analysing only those people with a hospital recorded diagnosis or who reported being diagnosed with depression by a professional affected their results.

The researchers looked specifically at whether genetic variations which have been found to be associated with obesity were also more common in people with depression.

As “markers” for obesity, if these genetic variations were more common in people with depression, this would suggest that obesity could be contributing to people’s risk of developing depression.

The researchers looked at 73 genetic variations which had been linked to having a higher BMI. The researchers excluded variants which had been linked to having a higher BMI but had stronger links to other conditions or traits such as smoking or lipid levels. Of the 73 variants, 43 were in or near to genes which could have an impact on brain and nervous system function and development (so they could theoretically be affecting depression risk directly) and 30 were not. Also, 14 of the variants were associated with increased BMI but reduced risk of metabolic disease (so these would not be influencing depression through these metabolic factors).

If the variants associated with a higher BMI, but not any of the metabolic consequences of obesity, were found to be more common in people with depression, this might suggest that the link between obesity and depression relates to psychological effects.

The researchers also looked at men and women separately, as it could be that the psychological impact of obesity might be greater in women because of issues around body image. They also repeated their analyses on a second sample of 45,591 people with depression and 97,647 controls from another study group (the Psychiatric Genetics Consortium).

What were the basic results?
The researchers found that individuals who were obese had a 45% higher chance of having depression than those in the healthy BMI range (odds ratio (OR) 1.45, 95% confidence interval (CI) 1.41 to 1.49). This link was stronger in women than in men.

Having a combination of genetic variants associated with a higher BMI (about 5kg/m2 higher) was associated with an 18% increase in the odds of having depression (OR 1.18, 95% CI 1.09 to 1.28). The link was slightly stronger in women than men, but the difference was not large enough to rule out that this occurred by chance.

The researchers found similar results when they carried out further analyses to make sure their findings were robust, for example, by excluding people without a hospital recorded diagnosis of depression.

The links to depression were stronger when looking at the BMI-linked variants which were also linked to brain or nervous system related genes. But again the difference was not large enough to rule out that it occurred by chance.

The link with depression was also found for BMI-linked variants which were associated with favourable metabolic profile, but only once data from the Biobank and Psychiatric Genetics Consortium samples were pooled.

How did the researchers interpret the results?
The researchers concluded that having a higher BMI is likely to contribute to directly increasing an individual’s chances of developing depression.

Some medications used to treat depression can cause weight gain. People who are depressed may be less likely to take good care of themselves, including eating healthily and taking regular exercise, and this may also impact their weight.

Conclusion

This study provides evidence that the link seen between obesity and depression may, at least in part, be due to a direct impact of weight on a person’s risk of depression.

This study was very large, and used many complex analyses to look at the relationship between weight, genetics, and depression. The researchers used a study design which aimed to remove the chance of factors other than weight impacting the results. They also carried out several additional analyses to test their results and make sure they were reliable.

For example, the way that people were classified as having or not having depression may not have been entirely accurate, as it was based partly on people’s reports of having seen a medical professional for “nerves, anxiety or depression”. Some people might have had depression but not sought help, or might not have had a diagnosis of depression had they been fully assessed. However, when the researchers excluded people who did not have a hospital recorded diagnosis of depression, they got similar results.

While this study contributes to what is known about the links between obesity and depression, there is still much to be learned. For example, the findings suggest the link may be psychological but researchers will now have to look more closely at how obesity might contribute to depression risk.

It is also worth bearing in mind that the causes of depression are likely to be complex, with many factors potentially playing a role. Also, the results may not apply to people of different ethnicities.

If you are overweight or obese and you are also troubled by low mood or depression then it may be a good idea to seek help for both issues at the same time.

What we do know is that mental and physical health are interrelated, and regular physical activity and eating healthily are likely to be beneficial for both.

Analysis by Bazian
Edited by NHS Website

Posted on Diet

Obesity – an over view from NHS Choices

Obesity - an overview

Obesity – an overview

The term “obese” describes a person who’s very overweight, with a lot of body fat.

It’s a common problem in the UK that’s estimated to affect around one in every four adults and around one in every five children aged 10 to 11.

Defining obesity

There are many ways in which a person’s health in relation to their weight can be classified, but the most widely used method is body mass index (BMI).

BMI is a measure of whether you’re a healthy weight for your height. You can use the BMI healthy weight calculator to work out your score.

For most adults, a BMI of:

18.5 to 24.9 means you’re a healthy weight

25 to 29.9 means you’re overweight

30 to 39.9 means you’re obese

40 or above means you’re severely obese

BMI isn’t used to definitively diagnose obesity, because people who are very muscular sometimes have a high BMI without excess fat. But for most people, BMI is a useful indication of whether they’re a healthy weight, overweight or obese.

A better measure of excess fat is waist circumference, which can be used as an additional measure in people who are overweight (with a BMI of 25 to 29.9) or moderately obese (with a BMI of 30 to 34.9).

Generally, men with a waist circumference of 94cm (37in) or more and women with a waist circumference of 80cm (about 31.5in) or more are more likely to develop obesity-related health problems.

Read more about diagnosing obesity.

Risks of obesity

It’s very important to take steps to tackle obesity because, as well as causing obvious physical changes, it can lead to a number of serious and potentially life-threatening conditions, such as:

type 2 diabetes

coronary heart disease

some types of cancer, such as breast cancer and bowel cancer

stroke

Obesity can also affect your quality of life and lead to psychological problems, such as depression and low self-esteem (see below for more information about the health problems associated with obesity).

Causes of obesity

Obesity is generally caused by consuming more calories – particularly those in fatty and sugary foods – than you burn off through physical activity. The excess energy is stored by the body as fat.

Obesity is an increasingly common problem because for many people modern living involves eating excessive amounts of cheap, high-calorie food and spending a lot of time sitting down, at desks, on sofas or in cars.

Read about why sitting too much is bad for your health.

There are also some underlying health conditions that can occasionally contribute to weight gain, such as an underactive thyroid gland (hypothyroidism), although these type of conditions don’t usually cause weight problems if they’re effectively controlled with medication.

Read more about the causes of obesity.

Treating obesity

The best way to treat obesity is to eat a healthy, reduced-calorie diet and exercise regularly. To do this you should:

eat a balanced, calorie-controlled diet as recommended by your GP or weight loss management health professional (such as a dietitian)

join a local weight loss group

take up activities such as fast walking, jogging, swimming or tennis for 150 to 300 minutes (two-and-a-half to five hours) a week

eat slowly and avoid situations where you know you could be tempted to overeat

You may also benefit from receiving psychological support from a trained healthcare professional to help change the way you think about food and eating.

If lifestyle changes alone don’t help you lose weight, a medication called orlistat may be recommended. If taken correctly, this medication works by reducing the amount of fat you absorb during digestion. Your GP will know whether orlistat is suitable for you.

In rare cases, weight loss surgery may be recommended.

Read more about the NHS weight loss guide and how obesity is treated.

Outlook

There’s no “quick fix” for obesity. Weight loss programmes take time and commitment, and work best when fully completed. The healthcare professionals involved with your care should provide encouragement and advice about how to maintain the weight loss achieved.

Regularly monitoring your weight, setting realistic goals and involving your friends and family with your attempts to lose weight can also help.

Remember that even losing what seems like a small amount of weight, such as 3% or more of your original body weight, and maintaining this for life, can significantly reduce your risk of developing obesity-related complications like diabetes and heart disease.

Couch to 5K

If it’s been a long time since you did any exercise, you should check out the NHS Choices Couch to 5K running plan.

It consists of podcasts delivered over the course of nine weeks and has been specifically designed for absolute beginners.

To begin with, you start running for short periods of time, and as the plan progresses, gradually increase the amount.

At the end of the nine weeks, you should be able to run for 30 minutes non-stop, which for most people is around five kilometres (3.1 miles).

Posted on Weight Loss

WHY AMERICA IS GETTING FATTER: THE SCARY TRUTH ABOUT OBESITY

The numbers don’t lie—obesity in America is a real and growing threat to the health and wellness of millions, both young and old.
According to the Center for Disease Control, 34.9% of U.S. adults are considered medically obese—that’s 78.6 million people in this country! But do you know how bad obesity is for the body? With the life-threatening illnesses and complications that come from being overweight, it’s no wonder that the “obesity epidemic” in the United States is inspiring all types of healthy living initiatives from the grocery store to Capitol Hill.

Please include attribution to Top Medical Assisting Programs with this graphic.

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Obesity in America by the Numbers

Forget the numbers on the scale and the clothing size you want to fit in—obesity has some even more startling numbers connected with it. According to the Center for Disease Control, a shocking 17% of children ages 2 to 19 are considered not just overweight, but obese. Obesity for adults is defined as a body mass index (BMI) of over 30.0. Illnesses caused by eating too unhealthily and carrying a harmful body weight are some of the leading causes of preventable death in this country—including heart disease, stroke, type 2 diabetes, and some forms of cancer. In fact, as reported by the Harvard School of Public Health, overweight people have 32% higher risk of developing coronary artery disease (CAD), while those who are obese have 81% higher risk!

With that in mind, consider that the National Institutes of Health estimate that 300,000 Americans die each year due to the obesity epidemic. That’s like the whole population of Cincinnati, Ohio being wiped out from obesity-related illnesses! On average, an obese individual’s annual medical costs are $1,429 higher than someone of healthy weight. That much money can pay for a whole family’s gym membership and some healthier food options.

Some Hidden Causes of Obesity

One of the best things you can do for your health is to take a good hard look at the food you eat. Huge contributors to the rise in obesity are the added fats, sugars, and chemicals lurking in foods that seem harmless. The New York Times reports that Americans eat 22 to 30 teaspoons of added sugar in their foods, with half of them coming from sugary drinks and sodas. And when you have a meal at a restaurant, you have no idea how many calories, grams of fat, or what types of ingredients are used to make your dish. So you might be looking at just one meal that packs a 1,500+ calorie punch—more than half the recommended daily intake for an average person. There has been a growing trend—and legislation in some states—that demands that food establishments list the calorie and fat content on menus to fully inform customers.

Combating Obesity in the United States

You may not be surprised to hear this, but preventing and combating the dangerous health effects of obesity have to do with exercise and eating habits that are often shaped when we’re young. Only 20.8% of adults over 18 years old meet the Physical Activity Guidelines for both muscle-strengthening and aerobic physical activity. Those guidelines recommend that Americans shoot for a minimum of 2.5 hours of moderate-intensity aerobic activity per week, reports the Harvard School of Public Health. Many gyms offer trial periods or discounted first classes so that you can try a particular type of exercise before you commit to membership fees. The key to consistent and goal-achieving weight loss and management is to find a type of exercise you enjoy doing!

Healthier eating is also crucial to maintaining a healthy weight and body mass index (BMI). Unfortunately, the Harvard School of Public Health reports that eating costs about $1.50 more per day than an unhealthy diet, which really isn’t too much to pad to your grocery budget.

There has also been a legislative move to end “food desserts”—a term for urban and rural areas that are more than a mile away from healthy, affordable food options in supermarkets or restaurants. The Healthy Food Financing Initiative is working to develop grocery stores, small retailers and corner stores, and farmers markets to offer healthy and affordable food options to their community.

What You Can Do
One of the best defenses against the slippery slope of ongoing weight gain is to be aware of your eating habits and establishing an exercise routine that you stick to. If you’re passionate about inspiring healthy habits in others, then consider pursuing a career in healthcare or nutrition. And share this infographic to alert your friends and family to the dangers that unhealthy eating can lead to!

Leave a comment Posted on Sleep disorders

Why lack of sleep is bad for your health and seven reasons why a good night’s sleep boost your health!

Why you need your sleep

Why you need your sleep


Many effects of a lack of sleep, such as feeling grumpy and not working at your best, are well known. But did you know that sleep deprivation can also have profound consequences on your physical health?

One in three of us suffers from poor sleep, with stress, computers and taking work home often blamed.

However, the cost of all those sleepless nights is more than just bad moods and a lack of focus.

Regular poor sleep puts you at risk of serious medical conditions, including obesity, heart disease and diabetes – and it shortens your life expectancy.

It’s now clear that a solid night’s sleep is essential for a long and healthy life.

How much sleep do we need?

Most of us need around eight hours of good-quality sleep a night to function properly – but some need more and some less. What matters is that you find out how much sleep you need and then try to achieve it.

As a general rule, if you wake up tired and spend the day longing for a chance to have a nap, it’s likely that you’re not getting enough sleep.

A variety of factors can cause poor sleep, including health conditions such as sleep apnoea. But in most cases, it’s due to bad sleeping habits.

Find out the common medical causes of fatigue.

What happens if I don’t sleep?

Everyone’s experienced the fatigue, short temper and lack of focus that often follow a poor night’s sleep.

An occasional night without sleep makes you feel tired and irritable the next day, but it won’t harm your health.

After several sleepless nights, the mental effects become more serious. Your brain will fog, making it difficult to concentrate and make decisions. You’ll start to feel down, and may fall asleep during the day. Your risk of injury and accidents at home, work and on the road also increases.

Find out how to tell if you’re too tired to drive.

If it continues, lack of sleep can affect your overall health and make you prone to serious medical conditions, such as obesity, heart disease, high blood pressure and diabetes.

Here are seven ways in which a good night’s sleep can boost your health:

1. Sleep boosts immunity

If you seem to catch every cold and flu that’s going around, your bedtime could be to blame. Prolonged lack of sleep can disrupt your immune system, so you’re less able to fend off bugs.

2. Sleep can slim you

Sleeping less may mean you put on weight! Studies have shown that people who sleep less than seven hours a day tend to gain more weight and have a higher risk of becoming obese than those who get seven hours of slumber.

It’s believed to be because sleep-deprived people have reduced levels of leptin (the chemical that makes you feel full) and increased levels of ghrelin (the hunger-stimulating hormone).

3. Sleep boosts mental wellbeing

Given that a single sleepless night can make you irritable and moody the following day, it’s not surprising that chronic sleep debt may lead to long-term mood disorders like depression and anxiety.

When people with anxiety or depression were surveyed to calculate their sleeping habits, it turned out that most of them slept for less than six hours a night.

4. Sleep prevents diabetes

Studies have suggested that people who usually sleep less than five hours a night have an increased risk of having or developing diabetes.

It seems that missing out on deep sleep may lead to type 2 diabetes by changing the way the body processes glucose – the high-energy carbohydrate that cells use for fuel.

5. Sleep increases sex drive

Men and women who don’t get enough quality sleep have lower libidos and less of an interest in sex, research shows.

Men who suffer from sleep apnoea – a disorder in which breathing difficulties lead to interrupted sleep – also tend to have lower testosterone levels, which can lower libido.

6. Sleep wards off heart disease

Long-standing sleep deprivation seems to be associated with increased heart rate, an increase in blood pressure and higher levels of certain chemicals linked with inflammation, which may put extra strain on your heart.

7. Sleep increases fertility

Difficulty conceiving a baby has been claimed as one of the effects of sleep deprivation, in both men and women. Apparently, regular sleep disruptions can cause trouble conceiving by reducing the secretion of reproductive hormones.

How to catch up on lost sleep

If you don’t get enough sleep, there’s only one way to compensate – getting more sleep.

It won’t happen with a single early night. If you’ve had months of restricted sleep, you’ll have built up a significant sleep debt, so expect recovery to take several weeks.

Starting on a weekend, try to add on an extra hour or two of sleep a night. The way to do this is to go to bed when you’re tired, and allow your body to wake you in the morning (no alarm clocks allowed!).

Expect to sleep for upwards of 10 hours a night at first. After a while, the amount of time you sleep will gradually decrease to a normal level.

Don’t rely on caffeine or energy drinks as a short-term pick-me-up. They may boost your energy and concentration temporarily, but can disrupt your sleep patterns even further in the long term.

Leave a comment Posted on Diet, Obesity, Weight Loss

Could discovery of ‘fat switch’ cure obesity?

Could discovery of 'fat switch' cure obesity?

Could discovery of ‘fat switch’ cure obesity?

 

Original article on NHS Choices here.

“Obesity cure possible after discovery of fat ‘switch’,” is the somewhat premature headline in The Daily Telegraph.

Researchers have identified a “biological switch” that controls when fat cells convert fat into energy for the body. But the headline fails to make it clear that this discovery was in mice, not humans.

Current thinking is that fat cells start off as “beige”, where they’re essentially in a neutral state. They can then be converted into either white or brown fat cells.

White fat cells store energy and can contribute towards obesity. Brown fat cells are primed to burn energy by warming the body.

It’s possible for white fat cells to be converted into brown fat cells – by fasting, for example – in a process known as browning. In some cases, brown fat cells can switch back to being white fat cells again.

This study looked at this process in mice and found a mechanism that controls this switch. It involved an area of the brain called the hypothalamus and a protein called TCPTP, which acts on insulin receptors.

Researchers found the switch was stuck in obese mice and they were in energy-storing mode all the time, promoting weight gain.

But we don’t yet know if the switch would be the same in humans, and to what extent it contributes to obesity.

Interfering with neural pathways in the brain could have unintended consequences, so any drugs developed to target the process would need thorough testing to make sure they’re safe.

For now, the best way to achieve a healthy weight is to stay activeand eat a balanced diet.

Where did the story come from?

The study was carried out by researchers from Monash University in Australia, and the Department of Neuronal Control of Metabolism in Cologne, University Hospital Cologne, the University of Cologne, and the National Center for Diabetes Research, all in Germany.

The research was funded by the NHMRC of Australia, the Diabetes Australia Research Trust, and the National Imaging Facility.

It was published in the peer-reviewed journal Cell Metabolism.

The UK media coverage of this research was generally accurate, although The Guardian failed to mention anywhere in their article the research was conducted in mice.

Any talk of a cure for obesity being found, as suggested by The Daily Telegraph, is premature.

The study’s results can’t be directly linked to human biology. There’s no way of knowing yet if fat control mechanisms in human brains work in the same way.

What kind of research was this?

This experimental research was carried out in mice to understand the mechanism behind the storage or expenditure of energy in normal and obese mice, as well as during feeding or fasting stages.

This kind of research is very useful for showing how biological mechanisms might potentially work in humans.

But the research is at a very early stage, and there’s a long way to go before therapies or treatments might be available for humans.

What did the research involve?

The researchers looked at brain scans, blood tests and metabolic measurements in mice to examine how the mechanisms in a part of the brain called the hypothalamus work in response to feeding and fasting, and see how these might potentially work in humans.

The hypothalamus is responsible for regulating a number of essential biological processes, including appetite, and regulating body temperature.

The specific area in the hypothalamus the researchers were interested in was the insulin receptor TCPTP.

The researchers looked at the mice’s ability to use energy just after a meal and store energy in between meals by preventing or allowing the action of insulin.

Insulin levels rise after eating as blood glucose levels rise, causing the brain to send signals to start “browning” fat so energy is expended. When insulin levels lower, energy starts to be conserved again.

The researchers looked at beige fat cells and their ability to switch between white fat cell-like states (energy storage) and brown-like states (energy expended).

They also looked at the mechanism that controls these beige fat cells, how this mechanism changes according to eating or fasting patterns (and therefore insulin levels), and whether there are any differences in this mechanism in obese mice.

What were the basic results?

The researchers found beige fat cells’ ability to switch between energy storage versus expenditure was important in a feeding versus fasting context.

They found this was co-ordinated by the hypothalamus and the action of TCPTP on insulin receptors in this area of the brain.

Hypothalamic TCPTP was increased during the fasting phase, which prevented insulin signalling, resulting in less browning of the white fat cells and therefore less energy expenditure.

Hypothalamic TCPTP decreased during the feeding phase, increasing insulin signalling and resulting in more browning of the white fat cells and more energy expended.

The ability to suppress the hypothalamic TCPTP as a result of feeding didn’t work as effectively in obese mice.

Removing hypothalamic TCPTP in obese mice restored browning of the beige fat cells after feeding, increasing energy expenditure once more to promote weight loss.

Mice without hypothalamic TCPTP didn’t become obese when overfed.

How did the researchers interpret the results?

The researchers concluded: “Our studies indicate that the energy expenditure specifically associated with feeding in chow-fed lean mice is reduced in diet-induced obesity.

“The promotion of feeding-induced energy expenditure may provide an approach by which to combat obesity.”

Conclusion

This early-stage research suggests there is potentially a mechanism by which energy expenditure and storage is controlled in normal-weight mice versus obese mice.

Removing a protein called hypothalamic TCPTP, which acts as the “switch” for fat storage, promoted weight loss in obese mice.

This might give us some insight into how weight loss could be promoted in obese humans by turning this switch off.

But at this stage, this is just a hypothesis – we can’t assume the same is true for humans. Many therapies and procedures that appear promising at the outset aren’t always successful in humans.

Given the major disease burden caused by obesity, finding ways to reduce its prevalence is a crucial area of research.

For now, the best way to achieve a healthy weight is to stay activeand eat a balanced diet.