Everyone seems to have a different opinion when it comes to how often towels and bed sheets should be washed. While many people might wonder whether days or weeks is best, in one survey from the United Kingdom, almost half of single men reported not washing their sheets for up to four months at a time.

It’s fairly clear that four months is too long to leave it, but what is the ideal frequency?

Bed linen and towels are quite different and so should be washed at different intervals. While every week or two will generally suffice for sheets, towels are best washed every few days.

Anyway, who doesn’t love the feeling of a fresh set of sheets or the smell of a newly laundered towel?

Why you should wash towels more often

When you dry yourself, you deposit thousands of skin cells and millions of microbes onto the towel. And because you use your towel to dry yourself after a shower or bath, your towel is regularly damp.

You also deposit a hefty amount of dead skin, microbes, sweat and oils onto your sheets every night. But unless you’re a prolific night sweater, your bedding doesn’t get wet after a night’s sleep.

Towels are also made of a thicker material than sheets and therefore tend to stay damp for longer.

So what is it about the dampness that causes a problem? Wet towels are a breeding ground for bacteria and moulds. Moulds especially love damp environments. Although mould won’t necessarily be visible (you would need significant growth to be able to see it) this can lead to an unpleasant smell.

As well as odours, exposure to these microbes in your towels and sheets can cause asthma, allergic skin irritations, or other skin infections.

So what’s the ideal frequency?

For bedding, it really depends on factors such as whether you have a bath or shower just before going to bed, or if you fall into bed after a long, sweaty day and have your shower in the morning. You will need to wash your sheets more regularly in the latter case. As a rule of thumb, once a week or every two weeks should be fine.

Towels should ideally be washed more regularly – perhaps every few days – while your facecloth should be cleaned after every use. Because it gets completely wet, it will be wet for a longer time, and retain more skin cells and microbes.

Wash your towels at a high temperature (for example, 65°C) as that will kill many microbes. If you are conscious of saving energy, you can use a lower temperature and add a cup of vinegar to the wash. The vinegar will kill microbes and prevent bad smells from developing.

Clean your washing machine regularly and dry the fold in the rubber after every wash, as this is another place microbes like to grow.

Smelly towels

What if you regularly wash your towels, but they still smell bad? One of the reasons for this pong could be that you’ve left them in the washing machine too long after the wash. Especially if it was a warm wash cycle, the time they’re warm and damp will allow microbes to happily grow. Under lab conditions the number of these bacteria can double every 30 minutes.

It’s important to hang your towel out to dry after use and not to leave towels in the washing machine after the cycle has finished. If possible, hang your towels and bedding out in the sun. That will dry them quickly and thoroughly and will foster that lovely fresh, clean cotton smell. Using a dryer is a good alternative if the weather is bad, but outdoors in the sun is always better if possible.

Also, even if your towel is going to be washed, don’t throw a wet towel into the laundry basket, as the damp, dirty towel will be an ideal place for microbes to breed. By the time you get to doing your washing, the towel and the other laundry around it may have acquired a bad smell. And it can be difficult to get your towels smelling fresh again.

What about ‘self-cleaning’ sheets and towels?

Some companies sell “quick-dry” towels or “self-cleaning” towels and bedding. Quick-dry towels are made from synthetic materials that are weaved in a way to allow them to dry quickly. This would help prevent the growth of microbes and the bad smells that develop when towels are damp for long periods of time.

But the notion of self-cleaning products is more complicated. Most of these products contain nanosilver or copper, antibacterial metals that kill micro-organisms. The antibacterial compounds will stop the growth of bacteria and can be useful to limit smells and reduce the frequency with which you need to clean your sheets and towels.

However, they’re not going to remove dirt like oils, skin flakes and sweat. So as much as I would love the idea of sheets and towels that clean themselves, that’s not exactly what happens.

Also, excessive use of antimicrobials such as nanosilver can lead to microbes becoming resistant to them.

Rietie Venter, Associate professor, Clinical and Health Sciences, University of South Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

If you’re one of the one in three Australians whose New Year’s resolution involved losing weight, it’s likely you’re now contemplating what weight-loss goal you should actually be working towards.

But type “setting a weight loss goal” into any online search engine and you’ll likely be left with more questions than answers.

Sure, the many weight-loss apps and calculators available will make setting this goal seem easy. They’ll typically use a body mass index (BMI) calculator to confirm a “healthy” weight and provide a goal weight based on this range.

Your screen will fill with trim-looking influencers touting diets that will help you drop ten kilos in a month, or ads for diets, pills and exercise regimens promising to help you effortlessly and rapidly lose weight.

Most sales pitches will suggest you need to lose substantial amounts of weight to be healthy – making weight loss seem an impossible task. But the research shows you don’t need to lose a lot of weight to achieve health benefits.

Using BMI to define our target weight is flawed

We’re a society fixated on numbers. So it’s no surprise we use measurements and equations to score our weight. The most popular is BMI, a measure of our body weight-to-height ratio.

BMI classifies bodies as underweight, normal (healthy) weight, overweight or obese and can be a useful tool for weight and health screening.

But it shouldn’t be used as the single measure of what it means to be a healthy weight when we set our weight-loss goals. This is because it:

• fails to consider two critical factors related to body weight and health – body fat percentage and distribution
• does not account for significant differences in body composition based on gender, ethnicity and age.

How does losing weight benefit our health?

Losing just 5–10% of our body weight – between 6 and 12kg for someone weighing 120kg – can significantly improve our health in four key ways.

1. Reducing cholesterol

Obesity increases the chances of having too much low-density lipoprotein (LDL) cholesterol – also known as bad cholesterol – because carrying excess weight changes how our bodies produce and manage lipoproteins and triglycerides, another fat molecule we use for energy.

Having too much bad cholesterol and high triglyceride levels is not good, narrowing our arteries and limiting blood flow, which increases the risk of heart disease, heart attack and stroke.

But research shows improvements in total cholesterol, LDL cholesterol and triglyceride levels are evident with just 5% weight loss.

2. Lowering blood pressure

Our blood pressure is considered high if it reads more than 140/90 on at least two occasions.

Excess weight is linked to high blood pressure in several ways, including changing how our sympathetic nervous system, blood vessels and hormones regulate our blood pressure.

Essentially, high blood pressure makes our heart and blood vessels work harder and less efficiently, damaging our arteries over time and increasing our risk of heart disease, heart attack and stroke.

Like the improvements in cholesterol, a 5% weight loss improves both systolic blood pressure (the first number in the reading) and diastolic blood pressure (the second number).

A meta-analysis of 25 trials on the influence of weight reduction on blood pressure also found every kilo of weight loss improved blood pressure by one point.

3. Reducing risk for type 2 diabetes

Excess body weight is the primary manageable risk factor for type 2 diabetes, particularly for people carrying a lot of visceral fat around the abdomen (belly fat).

Carrying this excess weight can cause fat cells to release pro-inflammatory chemicals that disrupt how our bodies regulate and use the insulin produced by our pancreas, leading to high blood sugar levels.

Type 2 diabetes can lead to serious medical conditions if it’s not carefully managed, including damaging our heart, blood vessels, major organs, eyes and nervous system.

Research shows just 7% weight loss reduces risk of developing type 2 diabetes by 58%.

4. Reducing joint pain and the risk of osteoarthritis

Carrying excess weight can cause our joints to become inflamed and damaged, making us more prone to osteoarthritis.

Observational studies show being overweight doubles a person’s risk of developing osteoarthritis, while obesity increases the risk fourfold.

Small amounts of weight loss alleviate this stress on our joints. In one study each kilogram of weight loss resulted in a fourfold decrease in the load exerted on the knee in each step taken during daily activities.

Focus on long-term habits

If you’ve ever tried to lose weight but found the kilos return almost as quickly as they left, you’re not alone.

An analysis of 29 long-term weight-loss studies found participants regained more than half of the weight lost within two years. Within five years, they regained more than 80%.

When we lose weight, we take our body out of its comfort zone and trigger its survival response. It then counteracts weight loss, triggering several physiological responses to defend our body weight and “survive” starvation.

Just as the problem is evolutionary, the solution is evolutionary too. Successfully losing weight long-term comes down to:

• losing weight in small manageable chunks you can sustain, specifically periods of weight loss, followed by periods of weight maintenance, and so on, until you achieve your goal weight

• making gradual changes to your lifestyle to ensure you form habits that last a lifetime.

Setting a goal to reach a healthy weight can feel daunting. But it doesn’t have to be a pre-defined weight according to a “healthy” BMI range. Losing 5–10% of our body weight will result in immediate health benefits.

At the Boden Group, Charles Perkins Centre, we are studying the science of obesity and running clinical trials for weight loss. You can register here to express your interest.

Nick Fuller, Charles Perkins Centre Research Program Leader, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.