People have a pretty intuitive sense of what is healthy – standing is better than sitting, exercise is great for overall health and getting good sleep is imperative.

However, if exercise in the evening may disrupt our sleep, or make us feel the need to be more sedentary to recover, a key question emerges – what is the best way to balance our 24 hours to optimise our health?

Our research attempted to answer this for risk factors for heart disease, stroke and diabetes. We found the optimal amount of sleep was 8.3 hours, while for light activity and moderate to vigorous activity, it was best to get 2.2 hours each.

Finding the right balance

Current health guidelines recommend you stick to a sensible regime of moderate-to vigorous-intensity physical activity 2.5–5 hours per week.

However mounting evidence now suggests how you spend your day can have meaningful ramifications for your health. In addition to moderate-to vigorous-intensity physical activity, this means the time you spend sitting, standing, doing light physical activity (such as walking around your house or office) and sleeping.

Our research looked at more than 2,000 adults who wore body sensors that could interpret their physical behaviours, for seven days. This gave us a sense of how they spent their average 24 hours.

At the start of the study participants had their waist circumference, blood sugar and insulin sensitivity measured. The body sensor and assessment data was matched and analysed then tested against health risk markers — such as a heart disease and stroke risk score — to create a model.

Using this model, we fed through thousands of permutations of 24 hours and found the ones with the estimated lowest associations with heart disease risk and blood-glucose levels. This created many optimal mixes of sitting, standing, light and moderate intensity activity.

When we looked at waist circumference, blood sugar, insulin sensitivity and a heart disease and stroke risk score, we noted differing optimal time zones. Where those zones mutually overlapped was ascribed the optimal zone for heart disease and diabetes risk.

You’re doing more physical activity than you think

We found light-intensity physical activity (defined as walking less than 100 steps per minute) – such as walking to the water cooler, the bathroom, or strolling casually with friends – had strong associations with glucose control, and especially in people with type 2 diabetes. This light-intensity physical activity is likely accumulated intermittently throughout the day rather than being a purposeful bout of light exercise.

Our experimental evidence shows that interrupting our sitting regularly with light-physical activity (such as taking a 3–5 minute walk every hour) can improve our metabolism, especially so after lunch.

While the moderate-to-vigorous physical activity time might seem a quite high, at more than 2 hours a day, we defined it as more than 100 steps per minute. This equates to a brisk walk.

It should be noted that these findings are preliminary. This is the first study of heart disease and diabetes risk and the “optimal” 24 hours, and the results will need further confirmation with longer prospective studies.

The data is also cross-sectional. This means that the estimates of time use are correlated with the disease risk factors, meaning it’s unclear whether how participants spent their time influences their risk factors or whether those risk factors influence how someone spends their time.

Australia’s adult physical activity guidelines need updating

Australia’s physical activity guidelines currently only recommend exercise intensity and time. A new set of guidelines are being developed to incorporate 24-hour movement. Soon Australians will be able to use these guidelines to examine their 24 hours and understand where they can make improvements.

While our new research can inform the upcoming guidelines, we should keep in mind that the recommendations are like a north star: something to head towards to improve your health. In principle this means reducing sitting time where possible, increasing standing and light-intensity physical activity, increasing more vigorous intensity physical activity, and aiming for a healthy sleep of 7.5–9 hours per night.

Beneficial changes could come in the form of reducing screen time in the evening or opting for an active commute over driving commute, or prioritising an earlier bed time over watching television in the evening.

It’s also important to acknowledge these are recommendations for an able adult. We all have different considerations, and above all, movement should be fun.

Christian Brakenridge, Postdoctoral research fellow at Swinburne University Centre for Urban Transitions, Swinburne University of Technology

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

Rice is a culinary staple in Australia and around the world.

It might seem like a given that brown rice is healthier than white and official public health resources often recommend brown rice instead of white as a “healthy swap”.

But Australians definitely prefer white rice over brown. So, what’s the difference, and what do we need to know when choosing rice?

What makes rice white or brown?

Rice “grains” are technically seeds. A complete, whole rice seed is called a “paddy”, which has multiple parts:

1. the “hull” is the hard outer layer which protects the seed
2. the “bran”, which is a softer protective layer containing the seed coat
3. the “germ” or the embryo, which is the part of the seed that would develop into a new plant if was germinated
4. the “endosperm”, which makes up most of the seed and is essentially the store of nutrients that feeds the developing plant as a seed grows into a plant.

Rice needs to be processed for humans to eat it.

Along with cleaning and drying, the hard hulls are removed since we can’t digest them. This is how brown rice is made, with the other three parts of the rice remaining intact. This means brown rice is regarded as a “wholegrain”.

White rice, however, is a “refined” grain, as it is further polished to remove the bran and germ, leaving just the endosperm. This is a mechanical and not a chemical process.

What’s the difference, nutritionally?

Keeping the bran and the germ means brown rice has more magnesium, phosphorus, potassium B vitamins (niacin, folate, riboflavin and pyridoxine), iron, zinc and fibre.

The germ and the bran also contain more bioactives (compounds in foods that aren’t essential nutrients but have health benefits), like oryzanols and phenolic compounds which have antioxidant effects.

But that doesn’t mean white rice is just empty calories. It still contains vitamins, minerals and some fibre, and is low in fat and salt, and is naturally gluten-free.

White and brown rice actually have similar amounts of calories (or kilojoules) and total carbohydrates.

There are studies that show eating more white rice is linked to a higher risk of type 2 diabetes. But it is difficult to know if this is down to the rice itself, or other related factors such as socioeconomic variables or other dietary patterns.

What about the glycaemic index?

The higher fibre means brown rice has a lower glycaemic index (GI), meaning it raises blood sugar levels more slowly. But this is highly variable between different rices within the white and brown categories.

The GI system uses low (less than 55), medium (55–70) and high (above 70) categories. Brown rices fall into the low and medium categories. White rices fall in the medium and high.

There are specific low-GI types available for both white and brown types. You can also lower the GI of rice by heating and then cooling it. This process converts some of the “available carbohydrates” into “resistant starch”, which then functions like dietary fibre.

Are there any benefits to white rice?

The taste and textural qualities of white and brown rices differ. White rice tends to have a softer texture and more mild or neutral flavour. Brown rice has a chewier texture and nuttier flavour.

So, while you can technically substitute brown rice into most recipes, the experience will be different. Or other ingredients may need to be added or changed to create the desired texture.

Removing more of the outer layers may also reduce the levels of contaminants such as pesticides.

We don’t just eat rice

Comparing white and brown rice seems like an easy way to boost nutritional value. But just because one food (brown rice) is more nutrient-dense doesn’t make the other food (white rice) “bad”.

Ultimately, it’s not often that we eat just rice, so we don’t need the rice we choose to be the perfect one. Rice is typically the staple base of a more complex dish. So, it’s probably more important to think about what we eat with rice.

Adding vegetables and lean proteins to rice-based dishes can easily add the micronutrients, bioactives and fibre that white rice is comparatively lacking, and this can likely do more to contribute to diet quality than eating brown rice instead.

Emma Beckett, Adjunct Senior Lecturer, Nutrition, Dietetics & Food Innovation – School of Health Sciences, UNSW Sydney

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