Not getting enough sleep is a common affliction in the modern age. If you don’t always get as many hours of shut-eye as you’d like, perhaps you were concerned by news of a recent study that found people who sleep less than six hours a night are at higher risk of type 2 diabetes.

So what can we make of these findings? It turns out the relationship between sleep and diabetes is complex.

The study

Researchers analysed data from the UK Biobank, a large biomedical database which serves as a global resource for health and medical research. They looked at information from 247,867 adults, following their health outcomes for more than a decade.

The researchers wanted to understand the associations between sleep duration and type 2 diabetes, and whether a healthy diet reduced the effects of short sleep on diabetes risk.

As part of their involvement in the UK Biobank, participants had been asked roughly how much sleep they get in 24 hours. Seven to eight hours was the average and considered normal sleep. Short sleep duration was broken up into three categories: mild (six hours), moderate (five hours) and extreme (three to four hours). The researchers analysed sleep data alongside information about people’s diets.

Some 3.2% of participants were diagnosed with type 2 diabetes during the follow-up period. Although healthy eating habits were associated with a lower overall risk of diabetes, when people ate healthily but slept less than six hours a day, their risk of type 2 diabetes increased compared to people in the normal sleep category.

The researchers found sleep duration of five hours was linked with a 16% higher risk of developing type 2 diabetes, while the risk for people who slept three to four hours was 41% higher, compared to people who slept seven to eight hours.

One limitation is the study defined a healthy diet based on the number of servings of fruit, vegetables, red meat and fish a person consumed over a day or a week. In doing so, it didn’t consider how dietary patterns such as time-restricted eating or the Mediterranean diet may modify the risk of diabetes among those who slept less.

Also, information on participants’ sleep quantity and diet was only captured at recruitment and may have changed over the course of the study. The authors acknowledge these limitations.

Why might short sleep increase diabetes risk?

In people with type 2 diabetes, the body becomes resistant to the effects of a hormone called insulin, and slowly loses the capacity to produce enough of it in the pancreas. Insulin is important because it regulates glucose (sugar) in our blood that comes from the food we eat by helping move it to cells throughout the body.

We don’t know the precise reasons why people who sleep less may be at higher risk of type 2 diabetes. But previous research has shown sleep-deprived people often have increased inflammatory markers and free fatty acids in their blood, which impair insulin sensitivity, leading to insulin resistance. This means the body struggles to use insulin properly to regulate blood glucose levels, and therefore increases the risk of type 2 diabetes.

Further, people who don’t sleep enough, as well as people who sleep in irregular patterns (such as shift workers), experience disruptions to their body’s natural rhythm, known as the circadian rhythm.

This can interfere with the release of hormones like cortisol, glucagon and growth hormones. These hormones are released through the day to meet the body’s changing energy needs, and normally keep blood glucose levels nicely balanced. If they’re compromised, this may reduce the body’s ability to handle glucose as the day progresses.

These factors, and others, may contribute to the increased risk of type 2 diabetes seen among people sleeping less than six hours.

While this study primarily focused on people who sleep eight hours or less, it’s possible longer sleepers may also face an increased risk of type 2 diabetes.

Research has previously shown a U-shaped correlation between sleep duration and type 2 diabetes risk. A review of multiple studies found getting between seven to eight hours of sleep daily was associated with the lowest risk. When people got less than seven hours sleep, or more than eight hours, the risk began to increase.

The reason sleeping longer is associated with increased risk of type 2 diabetes may be linked to weight gain, which is also correlated with longer sleep. Likewise, people who don’t sleep enough are more likely to be overweight or obese.

Good sleep, healthy diet

Getting enough sleep is an important part of a healthy lifestyle and may reduce the risk of type 2 diabetes.

Based on this study and other evidence, it seems that when it comes to diabetes risk, seven to eight hours of sleep may be the sweet spot. However, other factors could influence the relationship between sleep duration and diabetes risk, such as individual differences in sleep quality and lifestyle.

While this study’s findings question whether a healthy diet can mitigate the effects of a lack of sleep on diabetes risk, a wide range of evidence points to the benefits of healthy eating for overall health.

The authors of the study acknowledge it’s not always possible to get enough sleep, and suggest doing high-intensity interval exercise during the day may offset some of the potential effects of short sleep on diabetes risk.

In fact, exercise at any intensity can improve blood glucose levels.

Giuliana Murfet, Casual Academic, Faculty of Health, University of Technology Sydney and ShanShan Lin, Senior Lecturer, School of Public Health, University of Technology Sydney

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

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.