Why Weight Fluctuation Is Normal—And What to Do About It

When it comes to weight loss, we’ve been conditioned to believe that progress must follow a neat downward slope. However, new research from the CSIRO has thrown this myth out the window. And frankly, it’s about time.

A study, recently published in the Journal of Medical Internet Research, analysed data from more than 6,500 CSIRO Total Wellbeing Diet Online members over the course of a year. The verdict?

Fluctuations, plateaus and even small regains are all perfectly normal, and members who experienced the ups and downs in weight could still achieve clinically significant weight loss over time.

The CSIRO study identified the three most common weight loss patterns, which all included at least one three-month plateau:

15% of members lost weight for six months, then maintained their weight for a further six months, resulting in an average 11kg weight loss after a year (12% of their starting body weight)

11% lost weight in the first three months, then maintained for nine months, losing 5kg after a year (nearly 6% of their starting body weight)

9% lost weight for nine months, followed by three months of maintenance, resulting in an average 16kg loss (17% of their starting body weight).

Despite these ups and downs, two in three members lost at least five per cent of their starting body weight by 12 months, while one in three lost at least 10 per cent of their starting weight.

What did the data reveal was key to successful longer-term weight loss?

Well, rather than a steady decline in weight being the key to success, the study found that regular use of self-monitoring tools (these include weigh ins, food diary, menu plan, exercise plan, program content, forum, food search) and behaviours was a much stronger predictor of more consistent patterns of weight loss.

Those who engaged with self-monitoring tools regularly saw significantly better outcomes, while a highly engaged group of members lost more than 21% of their body weight.

So how do you stay motivated through a potential setback?

Remember that weight loss is a journey: weight loss isn’t a straight line. Periods of maintenance, small regains, and detours are normal. Starting with the right mindset can help to increase your chances of success. By preparing for a marathon and not a sprint, you’ll be ready for any hurdles thrown at you. Just keep sight of your destination.
Break your end game into achievable blocks: setting smaller, realistic goals can help maintain motivation and prevent overwhelm. Setting a specific goal for your weight loss will let you plan out specific steps necessary to lose weight. Most importantly, a goal allows you to focus on creating long-term habits that will allow you to maintain healthy results.
Set up regular check-ins with yourself: use a specific time each week, such as Sunday night, to review your meal plan, set new goals, and align with your schedule to stay on track.

Instead of giving up, reset. Introduce a new workout or style of cuisine, and consider how to stay on track, especially surrounding holiday periods!

Track (without obsessing) your food regularly: aim to log your meals at least three days a week to maintain awareness and accountability. Tools like the CSIRO Total Wellbeing Diet meal planner can help identify hidden habits - perhaps emotional eating patterns or a sneaky kilojoule creep.
Weigh in routinely: use scales or body measurements to track progress, but remember that fluctuations are normal. Recording your journey will help you stay on track. A support network through family, friends, or a community, such as the CSIRO Total Wellbeing Diet members, will help you be accountable and run the course.
Align your goals with what truly motivates you: whether it’s improved health, increased energy, or feeling more confident, staying connected to your ‘why’ will help keep you committed. An idea to keep you on track is to write it down and stick it to the wall. You need to be really clear on what you want to achieve and why it’s important to you, without comparing yourself to anyone else. It is hard to stay motivated unless you personally want to make the changes.

Nicole Pritchard is an Accredited Practising Dietitian and Exercise Physiologist with over 17 years of experience in the health industry, including corporate wellness, private health insurance as well as clinical dietetics, and is passionate about helping people develop lifelong habits and sustainable health changes.

Currently, she develops and delivers evidence-based health programs for weight management and chronic disease management and is skilled at being able to translate scientific evidence for a general audience.