Dr Nick Fuller
Leading Obesity Expert at the University of Sydney and founder of Interval Weight Loss.
Most weight loss programs promise fast results, but the reality is often disappointing—strict dieting, constant hunger, and eventual weight regain. That’s where Interval Weight Loss (IWL) stands out. Instead of forcing extreme calorie cuts or unsustainable meal plans, IWL works with your body’s natural biology to promote long-term, healthy weight loss.
A study from the University of Wollongong found that IWL helped 17.6% of participants achieve a 10% weight loss, while 62% lost at least 5% of their body weight. The CSIRO Total Wellbeing Diet had nearly half of its members hit that goal in just 12 weeks, while Weight Watchers (WW) Online users shed around 2.7 kg on average.
Turns out, slow and steady really does win the race. More importantly, they weren’t just dropping kilos—they were keeping them off. So, what makes IWL different? Let’s break it down.
A 2023 research from the University of Wollongong (UOW) put Interval Weight Loss (IWL) to the test in a real-world setting—and the results speak for themselves. Among those who followed the program for a year, 25.4% reached their goal weight, 17.6% lost at least 10% of their body weight, and 62% shed 5%. These figures might not sound as dramatic as crash diets promising rapid results, but here’s the key difference: participants weren’t just losing weight—they were keeping it off.
Unlike typical diets that lead to the all-too-familiar cycle of weight loss and regain, IWL’s structured approach helps prevent the body from triggering survival mechanisms that slow metabolism. The study found that alternating weight loss with maintenance phases helped participants avoid common dieting pitfalls like metabolic slowdowns and plateaus.
But IWL isn’t just about the number on the scale. The research also showed improvements in overall health, better eating habits, and a higher likelihood of sticking with the program compared to restrictive diets. With strong scientific backing and real-world results, IWL proves that sustainable weight loss isn’t about fighting your body—it’s about working with it.
Most weight loss programs follow the same flawed approach: restrict, lose weight quickly, then struggle to maintain it. Below are some reasons why they don’t work.
Extreme calorie restriction might help you lose weight in the short term, but it’s impossible to maintain. Cutting out entire food groups or living off meal replacements leads to cravings, fatigue, and ultimately, failure.
Losing weight too quickly sends your body into panic mode. Your metabolism slows down, and hunger hormones spike, making it almost inevitable that you’ll regain the weight, often with extra kilos on top.
When you drastically cut calories, your body adapts by conserving energy, slowing metabolism, and increasing hunger signals. This is why so many diets lead to frustration and weight regain once normal eating resumes.
Many diet programs push pre-packaged meals or shakes that are low in calories but also low in nutrients. While convenient, these products don’t teach sustainable eating habits, making long-term success unlikely.
From pricey subscription plans to specialty diet foods, traditional weight loss programs can drain your wallet. Once you stop paying, you often lose access to the tools and support needed to maintain progress.
Constantly counting calories, tracking macros, and worrying about every bite can take a toll on mental health. Many diets create an unhealthy relationship with food, leading to stress, guilt, and disordered eating patterns.
Your body has a natural weight range it tries to maintain, and extreme dieting fights against it. Without a strategy that works with this biological set point, long-term weight loss becomes nearly impossible.
IWL takes a completely different approach—one that’s backed by science and designed for long-term success.
Instead of drastic weight loss followed by inevitable regain, IWL focuses on gradual, sustainable weight loss. By alternating between weight loss and maintenance phases, your body has time to adjust, reducing the risk of plateaus and rebounds.
Rather than starving yourself, IWL prioritises metabolic health. By eating whole foods, managing stress, and incorporating movement, you support your metabolism instead of slowing it down.
IWL doesn’t require cutting out entire food groups or following unrealistic meal plans. You can still enjoy your favourite foods while making smarter choices that support long-term weight loss.
By focusing on mindful eating, habit-building, and a balanced approach to food, IWL helps break the diet-binge cycle. Instead of obsessing over calories, you learn to listen to your body’s hunger and fullness cues.
Unlike fad diets, IWL is grounded in scientific research. The recent study proves that this approach works, with participants achieving significant and lasting weight loss.
IWL isn’t just another weight loss program; it’s a scientifically proven method that works with your body, not against it. By focusing on metabolism, sustainable habits, and long-term success, it offers a refreshing alternative to restrictive diets and quick-fix solutions.
If you’re tired of the cycle of losing and regaining weight, it’s time to try an approach that actually works. IWL could be the last weight loss program you ever need.
Dr Nick Fuller is the founder of Interval Weight Loss and is a leading obesity expert at the University of Sydney with a Ph.D. in Obesity Treatment. Dr Fuller is also the author of three best-selling books and his work been published in top ranked journals in the medical field, including JAMA, Lancet and American Journal of Clinical Nutrition.