Globally, one in eight people are living with obesity. This is an issue because excess fat increases the risk of type 2 diabetes, heart disease and certain cancers.

Modifying your diet is important for managing obesity and preventing weight gain. This might include reducing your calorie intake, changing your eating patterns and prioritising healthy food.

But is one formula for weight loss more likely to result in success than another? Our new research compared three weight-loss methods, to see if one delivered more weight loss than the others:

• altering calorie distribution – eating more calories earlier rather than later in the day
• eating fewer meals
• intermittent fasting.

We analysed data from 29 clinical trials involving almost 2,500 people.

We found that over 12 weeks or more, the three methods resulted in similar weight loss: 1.4–1.8kg.

So if you do want to lose weight, choose a method that works best for you and your lifestyle.

Eating earlier in the day

When our metabolism isn’t functioning properly, our body can’t respond to the hormone insulin properly. This can lead to weight gain, fatigue and can increase the risk of a number of chronic diseases such as diabetes.

Eating later in the day – with a heavy dinner and late-night snacking – seems to lead to worse metabolic function. This means the body becomes less efficient at converting food into energy, managing blood sugar and regulating fat storage.

In contrast, consuming calories earlier in the day appears to improve metabolic function.

However, this might not be the case for everyone. Some people naturally have an evening “chronotype”, meaning they wake up and stay up later.

People with this chronotype appear to have less success losing weight, no matter the method. This is due to a combination of factors including genes, an increased likelihood to have a poorer diet overall and higher levels of hunger hormones.

Eating fewer meals

Skipping breakfast is common, but does it hinder weight loss? Or is a larger breakfast and smaller dinner ideal?

While frequent meals may reduce disease risk, recent studies suggest that compared to eating one to two meals a day, eating six times a day might increase weight loss success.

However, this doesn’t reflect the broader research, which tends to show consuming fewer meals can lead to greater weight loss. Our research suggests three meals a day is better than six. The easiest way to do this is by cutting out snacks and keeping breakfast, lunch and dinner.

Most studies compare three versus six meals, with limited evidence on whether two meals is better than three.

However, front-loading your calories (consuming most of your calories between breakfast and lunch) appears to be better for weight loss and may also help reduce hunger across the day. But more studies with a longer duration are needed.

Fasting, or time-restricted eating

Many of us eat over a period of more than 14 hours a day.

Eating late at night can throw off your body’s natural rhythm and alter how your organs function. Over time, this can increase your risk of type 2 diabetes and other chronic diseases, particularly among shift workers.

Time-restricted eating, a form of intermittent fasting, means eating all your calories within a six- to ten-hour window during the day when you’re most active. It’s not about changing what or how much you eat, but when you eat it.

Animal studies suggest time-restricted eating can lead to weight loss and improved metabolism. But the evidence in humans is still limited, especially about the long-term benefits.

It’s also unclear if the benefits of time-restricted eating are due to the timing itself or because people are eating less overall. When we looked at studies where participants ate freely (with no intentional calorie limits) but followed an eight-hour daily eating window, they naturally consumed about 200 fewer calories per day.

What will work for you?

In the past, clinicians have thought about weight loss and avoiding weight gain as a simile equation of calories in and out. But factors such as how we distribute our calories across the day, how often we eat and whether we eat late at night may also impact our metabolism, weight and health.

There are no easy ways to lose weight. So choose a method, or combination of methods, that suits you best. You might consider

• aiming to eat in an eight-hour window
• consuming your calories earlier, by focusing on breakfast and lunch
• opting for three meals a day, instead of six.

The average adult gains 0.4 to 0.7 kg per year. Improving the quality of your diet is important to prevent this weight gain and the strategies above might also help.

Finally, there’s still a lot we don’t know about these eating patterns. Many existing studies are short-term, with small sample sizes and varied methods, making it hard to make direct comparisons.

More research is underway, including well-controlled trials with larger samples, diverse populations and consistent methods. So hopefully future research will help us better understand how altering our eating patterns can result in better health.

Hayley O’Neill, Assistant Professor, Faculty of Health Sciences and Medicine, Bond University and Loai Albarqouni, Assistant Professor | NHMRC Emerging Leadership Fellow, Bond University

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.