You’re not in your 20s or 30s anymore and you know regular health checks are important. So you go to your GP. During the appointment they measure your waist. They might also check your weight. Looking concerned, they recommend some lifestyle changes.

GPs and health professionals commonly measure waist circumference as a vital sign for health. This is a better indicator than body mass index (BMI) of the amount of intra-abdominal fat. This is the really risky fat around and within the organs that can drive heart disease and metabolic disorders such as type 2 diabetes.

Men are at greatly increased risk of health issues if their waist circumference is greater than 102 centimetres. Women are considered to be at greater risk with a waist circumference of 88 centimetres or more. More than two-thirds of Australian adults have waist measurements that put them at an increased risk of disease. An even better indicator is waist circumference divided by height or waist-to-height ratio.

But we know people (especially women) have a propensity to gain weight around their middle during midlife, which can be very hard to control. Are they doomed to ill health? It turns out that, although such measurements are important, they are not the whole story when it comes to your risk of disease and death.

How much is too much?

Having a waist circumference to height ratio larger than 0.5 is associated with greater risk of chronic disease as well as premature death and this applies in adults of any age. A healthy waist-to-height ratio is between 0.4 to 0.49. A ratio of 0.6 or more places a person at the highest risk of disease.

Some experts recommend waist circumference be routinely measured in patients during health appointments. This can kick off a discussion about their risk of chronic diseases and how they might address this.

Excessive body fat and the associated health problems manifest more strongly during midlife. A range of social, personal and physiological factors come together to make it more difficult to control waist circumference as we age. Metabolism tends to slow down mainly due to decreasing muscle mass because people do less vigorous physical activity, in particular resistance exercise.

For women, hormone levels begin changing in mid-life and this also stimulates increased fat levels particularly around the abdomen. At the same time, this life phase (often involving job responsibilities, parenting and caring for ageing parents) is when elevated stress can lead to increased cortisol which causes fat gain in the abdominal region.

Midlife can also bring poorer sleep patterns. These contribute to fat gain with disruption to the hormones that control appetite.

Finally, your family history and genetics can make you predisposed to gaining more abdominal fat.

Why the waist?

This intra-abdominal or visceral fat is much more metabolically active (it has a greater impact on body organs and systems) than the fat under the skin (subcutaneous fat).

Visceral fat surrounds and infiltrates major organs such as the liver, pancreas and intestines, releasing a variety of chemicals (hormones, inflammatory signals, and fatty acids). These affect inflammation, lipid metabolism, cholesterol levels and insulin resistance, contributing to the development of chronic illnesses.

The issue is particularly evident during menopause. In addition to the direct effects of hormone changes, declining levels of oestrogen change brain function, mood and motivation. These psychological alterations can result in reduced physical activity and increased eating – often of comfort foods high in sugar and fat.

But these outcomes are not inevitable. Diet, exercise and managing mental health can limit visceral fat gains in mid-life. And importantly, the waist circumference (and ratio to height) is just one measure of human health. There are so many other aspects of body composition, exercise and diet. These can have much larger influence on a person’s health.

Muscle matters

The quantity and quality of skeletal muscle (attached to bones to produce movement) a person has makes a big difference to their heart, lung, metabolic, immune, neurological and mental health as well as their physical function.

On current evidence, it is equally or more important for health and longevity to have higher muscle mass and better cardiorespiratory (aerobic) fitness than waist circumference within the healthy range.

So, if a person does have an excessive waist circumference, but they are also sedentary and have less muscle mass and aerobic fitness, then the recommendation would be to focus on an appropriate exercise program. The fitness deficits should be addressed as priority rather than worry about fat loss.

Conversely, a person with low visceral fat levels is not necessarily fit and healthy and may have quite poor aerobic fitness, muscle mass, and strength. The research evidence is that these vital signs of health – how strong a person is, the quality of their diet and how well their heart, circulation and lungs are working – are more predictive of risk of disease and death than how thin or fat a person is.

For example, a 2017 Dutch study followed overweight and obese people for 15 years and found people who were very physically active had no increased heart disease risk than “normal weight” participants.

Getting moving is important advice

Physical activity has many benefits. Exercise can counter a lot of the negative behavioural and physiological changes that are occurring during midlife including for people going through menopause.

And regular exercise reduces the tendency to use food and drink to help manage what can be a quite difficult time in life.

Measuring your waist circumference and monitoring your weight remains important. If the measures exceed the values listed above, then it is certainly a good idea to make some changes. Exercise is effective for fat loss and in particular decreasing visceral fat with greater effectiveness when combined with dietary restriction of energy intake. Importantly, any fat loss program – whether through drugs, diet or surgery – is also a muscle loss program unless resistance exercise is part of the program. Talking about your overall health with a doctor is a great place to start.

Accredited exercise physiologists and accredited practising dietitians are the most appropriate allied health professionals to assess your physical structure, fitness and diet and work with you to get a plan in place to improve your health, fitness and reduce your current and future health risks.

Rob Newton, Professor of Exercise Medicine, Edith Cowan University

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

US-based online store iHerb has suspended sales of melatonin gummies to Australia. This comes after a rise in reports of non-fatal overdoses in Western Australia in children who took these popular supplements.

This latest move raises fresh concerns about the safety of these non-prescription sleep aids.

I have been a sleep researcher and a psychologist treating children with behavioural sleep problems for more than 20 years.

Here’s what’s great and not so great about using melatonin to help children sleep.

What is melatonin? Who uses it?

Melatonin is a naturally occurring hormone secreted in our brains. Its main function is to make us feel sleepy. A synthetic version is used in prescription and non-prescription products, for adults and for children who have trouble sleeping.

Melatonin prescriptions for children and adolescents with sleep difficulties have increased substantially around the world in recent years.

Melatonin available on prescription is an effective and relatively safe drug in children, particularly those with attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder. It is now the most commonly prescribed drug to treat insomnia in children and adolescents with neurodevelopmental disorders.

These children commonly have considerable difficulties getting to sleep, or getting back to sleep when they wake in the night. This can be distressing for the child and the whole family.

Guidelines for melatonin for these children suggest a low dose and only using it for a maximum two years. Melatonin does not appear to be addictive. So it seems like a good option for these families.

A rise in wider use

Up to one in four children have behavioural sleep problems, including children who are not neurodivergent, or who are developing typically.

So parents have turned to sourcing non-prescription melatonin, including melatonin gummies.

However, unlike for neurodivergent children, there are no scientific studies and therefore no evidence to demonstrate whether melatonin would work or pose a risk in typically developing children. There’s certainly no indication of how much children should take and for how long.

So melatonin is not usually recommended for children who are not neurodivergent.

Yet, it is widely available

In many countries including Australia, melatonin is classified as a pharmaceutical product. In Australia, the Therapeutic Goods Administration approves paediatric use for children with ADHD, autism and Smith-Magenis syndrome, and only on prescription.

In other countries, notably the United States, melatonin is categorised as a dietary supplement and is thought to be natural and safe. As such it is less tightly regulated than a pharmaceutical product.

As it’s available online, parents in countries with tighter restrictions, including Australia, can buy child-friendly melatonin gummies from the US, for example, and have it shipped. They can do this without a prescription or medical guidance.

Are melatonin gummies safe?

Accessing these gummies online for children without a prescription is at best concerning and at worst dangerous.

We don’t know how much melatonin is in these gummies. Studies show levels vary between brands of melatonin supplements and within the same brand. Melatonin levels range from practically zero to four times more than the amount stated on the label.

Some products also contained serotonin, which is concerning as this can interact with melatonin, and also affect a child’s mood.

There are also few studies on the long-term effects of taking melatonin, or what is a safe dose. So the risk of overdose is a real concern. Symptoms depend on many factors, including the age of the child. Symptoms include significant nausea, excessive sleepiness and migraine. The potential effects on other body systems and hormones have not been studied.

There have been deaths and hospital visits associated with the use of melatonin gummies in the US. There have been seven deaths in young children where the link to gummies has been suspected but not substantiated.

In Australia, there has been reports of a rise in queries about gummie overdoses to a poisons hotline.

There’s also the risk of toxicity with melatonin use. But there’s much we don’t know about how this happens, over what time frame, or its effects. Labels don’t always reflect what’s in the product so we don’t know if toxicity in children relates to those who have taken what’s recommended on the packet, or who have taken too many gummies by accident.

Melatonin gummies look like lollies. What child would not love to eat as many lollies as they can?

If you think your child has eaten too many gummies, they need emergency care.

So what are parents to do?

Sleep difficulties can be extremely distressing for the child and the whole family. But we need to treat melatonin with care. Buying melatonin gummies online is not the answer, despite many parents thinking they are safe and natural.

A medical professional can assess if a melatonin prescription is right for your child. They will also support you by recommending behavioural sleep strategies we know work, are sustainable and safe.

If you’d like support for your child’s sleep problems you can visit your GP and/or search for a trained sleep psychologist via the Australasian Sleep Association.

Sarah Blunden, Professor and Head of Paediatric Sleep Research, CQUniversity Australia

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