Few topics are more debated in health than the value of the humble bathroom scale. Some experts advocate daily self-weigh-ins to promote accountability for weight management, particularly when we’re following a diet and exercise program to lose weight.

Others suggest ditching self-weigh-ins altogether, arguing they can trigger negative psychological responses and unhealthy behaviours when we don’t like, or understand, the number we see on the scale.

Many, like me, recommend using scales to weigh yourself weekly, even when we’re not trying to lose weight. Here’s why.

1. Weighing weekly helps you manage your weight

Research confirms regular self-weighing is an effective weight loss and management strategy, primarily because it helps increase awareness of our current weight and any changes.

A systematic review of 12 studies found participants who weighed themselves weekly or daily over several months lost 1–3 BMI (body mass index) units more and regained less weight than participants who didn’t weight themselves frequently. The weight-loss benefit was evident with weekly weighing; there was no added benefit with daily weighing.

Self-weigh-ins are an essential tool for weight management as we age. Adults tend to gain weight progressively through middle age. While the average weight gain is typically between 0.5–1kg per year, this modest accumulation of weight can lead to obesity over time. Weekly weighing and keeping track of the results helps avoid unnecessary weight gain.

Tracking our weight can also help identify medical issues early. Dramatic changes in weight can be an early sign of some conditions, including problems with our thyroid, digestion and diabetes.

2. Weekly weighing accounts for normal fluctuations

Our body weight can fluctuate within a single day and across the days of the week. Studies show body weight fluctuates by 0.35% within the week and it’s typically higher after the weekend.

Daily and day-to-day body weight fluctuations have several causes, many linked to our body’s water content. The more common causes include:

The type of food we’ve consumed

When we’ve eaten a dinner higher in carbohydrates, we’ll weigh more the next day. This change is a result of our bodies temporarily carrying more water. We retain 3–4 grams of water per gram of carbohydrate consumed to store the energy we take from carbs.

Our water content also increases when we consume foods higher in salt. Our bodies try to maintain a balance of sodium and water. When the concentration of salt in our bloodstream increases, a mechanism is triggered to restore balance by retaining water to dilute the excess salt.

Our food intake

Whether it’s 30 grams of nuts or 65 grams of lean meat, everything we eat and drink has weight, which increases our body weight temporarily while we digest and metabolise what we’ve consumed.

Our weight also tends to be lower first thing in the morning after our food intake has been restricted overnight and higher in the evening after our daily intake of food and drinks.

Exercise

If we weigh ourselves at the gym after a workout, there’s a good chance we’ll weigh less due to sweat-induced fluid loss. The amount of water lost varies depending on things like our workout intensity and duration, the temperature and humidity, along with our sweat rate and hydration level. On average, we lose 1 litre of sweat during an hour of moderate-intensity exercise.

Hormonal changes

Fluctuations in hormones within your menstrual cycle can also affect fluid balance. Women may experience fluid retention and temporarily gain 0.5–2kg of weight at this time. Specifically, the luteal phase, which represents the second half of a woman’s cycle, results in a shift of fluid from your blood plasma to your cells, and bloating.

Bowel movements

Going to the bathroom can lead to small but immediate weight loss as waste is eliminated from the body. While the amount lost will vary, we generally eliminate around 100 grams of weight through our daily bowel movements.

All of these fluctuations are normal, and they’re not indicative of significant changes in our body fat or muscle mass. However, seeing these fluctuations can lead to unnecessary stress and a fixation with our weight.

3. Weekly weighing avoids scale obsession and weight-loss sabotage

Weighing too frequently can create an obsession with the number on the scales and do more harm than good.

Often, our reaction when we see this number not moving in the direction we want or expect is to further restrict our food intake or embark on fad dieting. Along with not being enjoyable or sustainable, fad diets also ultimately increase our weight gain rather than reversing it.

This was confirmed in a long-term study comparing intentional weight loss among more than 4,000 twins. The researchers found the likelihood of becoming overweight by the age of 25 was significantly greater for a twin who dieted to lose 5kg or more. This suggests frequent dieting makes us more susceptible to weight gain and prone to future weight gain.

So what should you do?

Weighing ourselves weekly gives a more accurate measure of our weight trends over time.

Aim to weigh yourself on the same day, at the same time and in the same environment each week – for example, first thing every Friday morning when you’re getting ready to take a shower, after you’ve gone to the bathroom, but before you’ve drunk or eaten anything.

Use the best quality scales you can afford. Change the batteries regularly and check their accuracy by using a “known” weight – for example, a 10kg weight plate. Place the “known” weight on the scale and check the measurement aligns with the “known” weight.

Remember, the number on the scale is just one part of health and weight management. Focusing solely on it can overshadow other indicators, such as how your clothes fit. It’s also essential to pay equal attention to how we’re feeling, physically and emotionally.

Stop weighing yourself – at any time interval – if it’s triggering anxiety or stress, and get in touch with a health-care professional to discuss this.

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.

Plastic is in our clothes, cars, mobile phones, water bottles and food containers. But recent research adds to growing concerns about the impact of tiny plastic fragments on our health.

A study from the United States has, for the first time, found microplastics in human brains. The study, which has yet to be independently verified by other scientists, has been described in the media as scary, shocking and alarming.

But what exactly are microplastics? What do they mean for our health? Should we be concerned?

What are microplastics? Can you see them?

We often consider plastic items to be indestructible. But plastic breaks down into smaller particles. Definitions vary but generally microplastics are smaller than five millimetres.

This makes some too small to be seen with the naked eye. So, many of the images the media uses to illustrate articles about microplastics are misleading, as some show much larger, clearly visible pieces.

Microplastics have been reported in many sources of drinking water and everyday food items. This means we are constantly exposed to them in our diet.

Such widespread, chronic (long-term) exposure makes this a serious concern for human health. While research investigating the potential risk microplastics pose to our health is limited, it is growing.

How about this latest study?

The study looked at concentrations of microplastics in 51 samples from men and women set aside from routine autopsies in Albuquerque, New Mexico. Samples were from the liver, kidney and brain.

These tiny particles are difficult to study due to their size, even with a high-powered microscope. So rather than trying to see them, researchers are beginning to use complex instruments that identify the chemical composition of microplastics in a sample. This is the technique used in this study.

The researchers were surprised to find up to 30 times more microplastics in brain samples than in the liver and kidney.

They hypothesised this could be due to high blood flow to the brain (carrying plastic particles with it). Alternatively, the liver and kidneys might be better suited to dealing with external toxins and particles. We also know the brain does not undergo the same amount of cellular renewal as other organs in the body, which could make the plastics linger here.

The researchers also found the amount of plastics in brain samples increased by about 50% between 2016 and 2024. This may reflect the rise in environmental plastic pollution and increased human exposure.

The microplastics found in this study were mostly composed of polyethylene. This is the most commonly produced plastic in the world and is used for many everyday products, such as bottle caps and plastic bags.

This is the first time microplastics have been found in human brains, which is important. However, this study is a “pre-print”, so other independent microplastics researchers haven’t yet reviewed or validated the study.

How do microplastics end up in the brain?

Microplastics typically enter the body through contaminated food and water. This can disrupt the gut microbiome (the community of microbes in your gut) and cause inflammation. This leads to effects in the whole body via the immune system and the complex, two-way communication system between the gut and the brain. This so-called gut-brain axis is implicated in many aspects of health and disease.

We can also breathe in airborne microplastics. Once these particles are in the gut or lungs, they can move into the bloodstream and then travel around the body into various organs.

Studies have found microplastics in human faeces, joints, livers, reproductive organs, blood, vessels and hearts.

Microplastics also migrate to the brains of wild fish. In mouse studies, ingested microplastics are absorbed from the gut into the blood and can enter the brain, becoming lodged in other organs along the way.

To get into brain tissue, microplastics must cross the blood-brain-barrier, an intricate layer of cells that is supposed to keep things in the blood from entering the brain.

Although concerning, this is not surprising, as microplastics must cross similar cell barriers to enter the urine, testes and placenta, where they have already been found in humans.

Is this a health concern?

We don’t yet know the effects of microplastics in the human brain. Some laboratory experiments suggest microplastics increase brain inflammation and cell damage, alter gene expression and change brain structure.

Aside from the effects of the microplastic particles themselves, microplastics might also pose risks if they carry environmental toxins or bacteria into and around the body.

Various plastic chemicals could also leach out of the microplastics into the body. These include the famous hormone-disrupting chemicals known as BPAs.

But microplastics and their effects are difficult to study. In addition to their small size, there are so many different types of plastics in the environment. More than 13,000 different chemicals have been identified in plastic products, with more being developed every year.

Microplastics are also weathered by the environment and digestive processes, and this is hard to reproduce in the lab.

A goal of our research is to understand how these factors change the way microplastics behave in the body. We plan to investigate if improving the integrity of the gut barrier through diet or probiotics can prevent the uptake of microplastics from the gut into the bloodstream. This may effectively stop the particles from circulating around the body and lodging into organs.

How do I minimise my exposure?

Microplastics are widespread in the environment, and it’s difficult to avoid exposure. We are just beginning to understand how microplastics can affect our health.

Until we have more scientific evidence, the best thing we can do is reduce our exposure to plastics where we can and produce less plastic waste, so less ends up in the environment.

An easy place to start is to avoid foods and drinks packaged in single-use plastic or reheated in plastic containers. We can also minimise exposure to synthetic fibres in our home and clothing.

Sarah Hellewell, Senior Research Fellow, The Perron Institute for Neurological and Translational Science, and Research Fellow, Faculty of Health Sciences, Curtin University; Anastazja Gorecki, Teaching & Research Scholar, School of Health Sciences, University of Notre Dame Australia, and Charlotte Sofield, PhD Candidate, studying microplastics and gut/brain health, University of Notre Dame Australia

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