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.

What’s the difference? is a new editorial product that explains the similarities and differences between commonly confused health and medical terms, and why they matter.

Vegan and vegetarian diets are plant-based diets. Both include plant foods, such as fruits, vegetables, legumes and whole grains.

But there are important differences, and knowing what you can and can’t eat when it comes to a vegan and vegetarian diet can be confusing.

So, what’s the main difference?

What’s a vegan diet?

A vegan diet is an entirely plant-based diet. It doesn’t include any meat and animal products. So, no meat, poultry, fish, seafood, eggs, dairy or honey.

What’s a vegetarian diet?

A vegetarian diet is a plant-based diet that generally excludes meat, poultry, fish and seafood, but can include animal products. So, unlike a vegan diet, a vegetarian diet can include eggs, dairy and honey.

But you may be wondering why you’ve heard of vegetarians who eat fish, vegetarians who don’t eat eggs, vegetarians who don’t eat dairy, and even vegetarians who eat some meat. Well, it’s because there are variations on a vegetarian diet:

• a lacto-ovo vegetarian diet excludes meat, poultry, fish and seafood, but includes eggs, dairy and honey
• an ovo-vegetarian diet excludes meat, poultry, fish, seafood and dairy, but includes eggs and honey
• a lacto-vegetarian diet excludes meat, poultry, fish, seafood and eggs, but includes dairy and honey
• a pescatarian diet excludes meat and poultry, but includes eggs, dairy, honey, fish and seafood
• a flexitarian, or semi-vegetarian diet, includes eggs, dairy and honey and may include small amounts of meat, poultry, fish and seafood.

Are these diets healthy?

A 2023 review looked at the health effects of vegetarian and vegan diets from two types of study.

Observational studies followed people over the years to see how their diets were linked to their health. In these studies, eating a vegetarian diet was associated with a lower risk of developing cardiovascular disease (such as heart disease or a stroke), diabetes, hypertension (high blood pressure), dementia and cancer.

For example, in a study of 44,561 participants, the risk of heart disease was 32% lower in vegetarians than non-vegetarians after an average follow-up of nearly 12 years.

Further evidence came from randomised controlled trials. These instruct study participants to eat a specific diet for a specific period of time and monitor their health throughout. These studies showed eating a vegetarian or vegan diet led to reductions in weight, blood pressure, and levels of unhealthy cholesterol.

For example, one analysis combined data from seven randomised controlled trials. This so-called meta-analysis included data from 311 participants. It showed eating a vegetarian diet was associated with a systolic blood pressure (the first number in your blood pressure reading) an average 5 mmHg lower compared with non-vegetarian diets.

It seems vegetarian diets are more likely to be healthier, across a number of measures.

For example, a 2022 meta-analysis combined the results of several observational studies. It concluded a vegetarian diet, rather than vegan diet, was recommended to prevent heart disease.

There is also evidence vegans are more likely to have bone fractures than vegetarians. This could be partly due to a lower body-mass index and a lower intake of nutrients such as calcium, vitamin D and protein.

But it can be about more than just food

Many vegans, where possible, do not use products that directly or indirectly involve using animals.

So vegans would not wear leather, wool or silk clothing, for example. And they would not use soaps or candles made from beeswax, or use products tested on animals.

The motivation for following a vegan or vegetarian diet can vary from person to person. Common motivations include health, environmental, ethical, religious or economic reasons.

And for many people who follow a vegan or vegetarian diet, this forms a central part of their identity.

So, should I adopt a vegan or vegetarian diet?

If you are thinking about a vegan or vegetarian diet, here are some things to consider:

• eating more plant foods does not automatically mean you are eating a healthier diet. Hot chips, biscuits and soft drinks can all be vegan or vegetarian foods. And many plant-based alternatives, such as plant-based sausages, can be high in added salt
• meeting the nutrient intake targets for vitamin B12, iron, calcium, and iodine requires more careful planning while on a vegan or vegetarian diet. This is because meat, seafood and animal products are good sources of these vitamins and minerals
• eating a plant-based diet doesn’t necessarily mean excluding all meat and animal products. A healthy flexitarian diet prioritises eating more whole plant-foods, such as vegetables and beans, and less processed meat, such as bacon and sausages
• the Australian Dietary Guidelines recommend eating a wide variety of foods from the five food groups (fruit, vegetables, cereals, lean meat and/or their alternatives and reduced-fat dairy products and/or their alternatives). So if you are eating animal products, choose lean, reduced-fat meats and dairy products and limit processed meats.

Katherine Livingstone, NHMRC Emerging Leadership Fellow and Senior Research Fellow at the Institute for Physical Activity and Nutrition, Deakin University

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