Do you struggle to eat your fruits and vegetables? You are not alone. Less than 5% of Australians eat the recommended serves of fresh produce each day (with 44% eating enough fruit but only 6% eating the recommended vegetables).

Adults should aim to eat at least five serves of vegetables (or roughly 375 grams) and two serves of fruit (about 300 grams) each day. Fruits and vegetables help keep us healthy because they have lots of nutrients (vitamins, minerals and fibre) and health-promoting bioactive compounds (substances not technically essential but which have health benefits) without having many calories.

So, if you are having trouble eating the rainbow, you might be wondering – is it OK to drink your fruits and vegetables instead in a juice or smoothie? Like everything in nutrition, the answer is all about context.

It might help overcome barriers

Common reasons for not eating enough fruits and vegetables are preferences, habits, perishability, cost, availability, time and poor cooking skills. Drinking your fruits and vegetables in juices or smoothies can help overcome some of these barriers.

Juicing or blending can help disguise tastes you don’t like, like bitterness in vegetables. And it can blitz imperfections such as bruises or soft spots. Preparation doesn’t take much skill or time, particularly if you just have to pour store-bought juice from the bottle. Treating for food safety and shipping time does change the make up of juices slightly, but unsweetened juices still remain significant sources of nutrients and beneficial bioactives.

Juicing can extend shelf life and reduce the cost of nutrients. In fact, when researchers looked at the density of nutrients relative to the costs of common foods, fruit juice was the top performer.

So, drinking my fruits and veggies counts as a serve, right?

How juice is positioned in healthy eating recommendations is a bit confusing. The Australian Dietary Guidelines include 100% fruit juice with fruit but vegetable juice isn’t mentioned. This is likely because vegetable juices weren’t as common in 2013 when the guidelines were last revised.

The guidelines also warn against having juice too often or in too high amounts. This appears to be based on the logic that juice is similar, but not quite as good as, whole fruit. Juice has lower levels of fibre compared to fruits, with fibre important for gut health, heart health and promoting feelings of fullness. Juice and smoothies also release the sugar from the fruit’s other structures, making them “free”. The World Health Organization recommends we limit free sugars for good health.

But fruit and vegetables are more than just the sum of their parts. When we take a “reductionist” approach to nutrition, foods and drinks are judged based on assumptions made about limited features such as sugar content or specific vitamins.

But these features might not have the impact we logically assume because of the complexity of foods and people. When humans eat varied and complex diets, we don’t necessarily need to be concerned that some foods are lower in fibre than others. Juice can retain the nutrients and bioactive compounds of fruit and vegetables and even add more because parts of the fruit we don’t normally eat, like the skin, can be included.

So, it is healthy then?

A recent umbrella review of meta-analyses (a type of research that combines data from multiple studies of multiple outcomes into one paper looked at the relationship between 100% juice and a range of health outcomes.

Most of the evidence showed juice had a neutral impact on health (meaning no impact) or a positive one. Pure 100% juice was linked to improved heart health and inflammatory markers and wasn’t clearly linked to weight gain, multiple cancer types or metabolic markers (such as blood sugar levels).

Some health risks linked to drinking juice were reported: death from heart disease, prostate cancer and diabetes risk. But the risks were all reported in observational studies, where researchers look at data from groups of people collected over time. These are not controlled and do not record consumption in the moment. So other drinks people think of as 100% fruit juice (such as sugar-sweetened juices or cordials) might accidentally be counted as 100% fruit juice. These types of studies are not good at showing the direct causes of illness or death.

What about my teeth?

The common belief juice damages teeth might not stack up. Studies that show juice damages teeth often lump 100% juice in with sweetened drinks. Or they use model systems like fake mouths that don’t match how people drinks juice in real life. Some use extreme scenarios like sipping on large volumes of drink frequently over long periods of time.

Juice is acidic and does contain sugars, but it is possible proper oral hygiene, including rinsing, cleaning and using straws can mitigate these risks.

Again, reducing juice to its acid level misses the rest of the story, including the nutrients and bioactives contained in juice that are beneficial to oral health.

So, what should I do?

Comparing whole fruit (a food) to juice (a drink) can be problematic. They serve different culinary purposes, so aren’t really interchangeable.

The Australian Guide to Healthy Eating recommends water as the preferred beverage but this assumes you are getting all your essential nutrients from eating.

Where juice fits in your diet depends on what you are eating and what other drinks it is replacing. Juice might replace water in the context of a “perfect” diet. Or juice might replace alcohol or sugary soft drinks and make the relative benefits look very different.

On balance

Whether you want to eat your fruits and vegetables or drink them comes down to what works for you, how it fits into the context of your diet and your life.

Smoothies and juices aren’t a silver bullet, and there is no evidence they work as a “cleanse” or detox. But, with society’s low levels of fruit and vegetable eating, having the option to access nutrients and bioactives in a cheap, easy and tasty way shouldn’t be discouraged either.

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.

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.