Top nutritionist talks long term weight loss - what are your chances of keeping the kilos off?

Top nutritionist, Mikki Williden, breaks down the long term dynamics of weight loss to help be successful in hitting your weight management goals.

There’s a pervading myth out there that diets (and weight loss) do not work. Regardless of what you do, the idea that eating less and moving more will, frankly, make you fatter in the long run.

There’s no question that diets work in the short term. The notion of both restricting something in the diet (be it a macronutrient, the eating window or focusing on calories) absolutely results in weight loss. Because regardless of the lever you pull, these all reduce the calories coming in and it can seem almost effortless if you hit on an approach that suits you most. People who are successful with low carb, intermittent fasting, tracking their calories or focusing on increasing protein end up find their approach an easy way to reduce calories without having to think about it. So, for them, it’s not restriction per se. And anyone can white knuckle a diet approach and lose weight over 3-6 months. But if you look at the literature on fat loss, the long-term results are underwhelming at best. 

Dulloo and Montani write that the paradox with weight loss is that people tend to gain back weight and then some after dieting, with up to two-thirds of the weight lost being regained in a year, and almost all of it within 5 years. They also state that those most at risk of weight regain (and the subsequent metabolic challenges this brings) are people who sit within the normal-weight category.  The people with less body fat to lose are more at risk of losing muscle mass which then puts them at risk of ‘overshooting’ with fat mass when baseline eating is resumed (as this is what the body prioritises, not the recovery of muscle tissue). Regardless of starting body weight, the changes that occur to appetite hormones (as described in this study) also drive increased hunger when dieting, which, when combined with lower energy requirements due to metabolic adaptation and less overall energy needs, increases the risk of weight regain. More recent systematic reviews support this pattern of weight regain, showing that while weight loss is achievable, long-term maintenance is the real challenge. There is plenty of evidence to show modest reductions in weight (5% of body weight) can improve health markers, however the real risk of weight regain exists without sustained behavioural changes and support.

As mentioned above, one of the main reasons diets “don’t work” long-term is due to the body’s natural biological adaptations:

• Reduced resting metabolic rate (your body burns fewer calories at rest)

• Increased hunger hormones (like ghrelin)

• Decreased satiety hormones (like leptin, which drops with a reduction in body fat)

• Heightened food reward signalling in the brain

These changes create a powerful physiological drive to regain the lost weight. The body essentially acts as though it's trying to "survive a famine," making weight maintenance feel like a constant uphill battle. Weight regain after weight loss is driven by both psychological traits such as low self-efficacy, impulsiveness, and emotional eating, and neurobiological changes, including heightened brain reward responses to food and reduced self-regulation. In fact, the brain feels hungry for an additional 100 Calories for every 1 kilogram of weight lost. These factors combine with hormonal and metabolic adaptations (e.g. increased ghrelin, reduced leptin) to create a strong biological drive to eat and regain lost weight. This is especially true in the world of highly processed food which can encourage overeating despite dieting status.

All of this is discouraging. However, as someone who spends my time supporting people through weight loss approaches and then maintaining their weight (along with so many of my colleagues) there are features of successful plans that are missing from the body of literature around obesity and dieting.

Most published research in obesity literature that reports underwhelming results from either the diet itself OR the ability to maintain weight loss are using methods for fat loss which are no longer considered best practice. These rely heavily on low calorie, low protein eating approaches, with exercise either not included or a focus on aerobic training. Even those that are higher protein for the calories provided don’t result in lasting weight loss. As a practitioner this is a feature of a few things. While that weight loss achieved is great for improving health, the underwhelming part of it is the small amount of weight lost as an individual - if someone is on a 1200 Cal diet (or prescribed this) for 12 months and only loses 8 kg with a starting weight that puts their BMI over 30 (and they are sedentary, which is often the target population) the math doesn’t add up - and adherence is likely the big sticking point.

Protein intake: if set at 15-20% calories in a fat loss plan, it still ends up being low in comparison to other nutrients. Protein targets should be set at grams/kg body weight (not as a percentage of calories, which is arbitrary)

Most obesity research (large scale studies) don’t often focus on exercise and instead focus on diet - this might be because of the logistics and costs of putting in a training plan that (or one that is supervised). A diet without exercise results in a softer, smaller version of the starting weight (hello, Amway diet)

Most start with intensive coaching that tapers off once weight loss has been achieved. The diet after the diet is THE most important thing. People have almost never experienced eating at maintenance and would have no idea how to do this. This in my experience is a hard place to navigate. Most follow up studies are ones where the researchers ‘leave them be’ to see how the go. I’ll tell you now, as a clinician, this goes south. Fast.

The focus on mindset isn’t often part of the plan OR (again) it’s not a feature of the long term follow up. Look, diet is a work on. It isn’t something you can spend three weeks, 8 weeks, 16 weeks or even 6 months focusing on and expect that you now have the tools. The sooner you accept that this is literally a work on for the rest of your life (and the diet and exercise is the easiest part) the more successful you will be. You are literally unravelling DECADES of behaviour that can’t be reversed in months. This is why weight loss is relatively simple (and arguably easy) yet maintaining it is nigh on impossible for most. That doesn’t, though, make the calories in, calories out model a myth.

Sick of starting over every Monday? Join Mikki Williden’s “Mondays Matter” – an 8-week programme that takes the guesswork (and guilt) out of fat loss. It combines high-protein, veggie-packed eating with protein-sparing modified fast (PSMF) days, time-restricted eating, and regular lifestyle breaks – so you can make real progress without feeling deprived.

You’ll get:

• Structured meal + strength plans

• Fortnightly Zoom calls and printable workbooks

• 24/7 support inside a private coaching group

Mikki has been running this since 2021 and thousands of people have called it “life-changing” – with better energy, body confidence, and freedom from all-or-nothing thinking. They come for the physical transformation but experience so much more.

Programme kicks off Monday 28 July: https://www.mikkiwilliden.com/mondays-matter