Niki Bezzant: Why does weight loss plateau?

When you're changing the way you eat, when you're changing your activity, the rate at which you lose weight won't necessarily be consistent. Photo / 123rf

Why does weight loss plateau? It's a common question, and the subject of a reader email.

Bob, who's in his 70s, writes:

"I recently reached an all-time high of 98.5 kilos after recovering from open heart surgery ... A month ago I set my own diet of reduction in carbs, smaller meals, very little alcohol and no pies or cakes (a weakness). This has been accompanied by a daily regime of 7km on the exercycle, 10 minutes on vibrating machine, 2x40 crunches and a daily walk of around 4km. Results have been good and I'm down to 93kg … however I have now plateaued and no matter what I do, I cannot get under 93."

Bob - though he's done really well - is understandably frustrated. What he expresses is a common problem for people when they embark on weight-loss programmes. The weight comes off encouragingly at the start, then seems to stall, even when you continue eating less. It's enough to make you throw up your hands and give up (which often happens). So what's going on? And is there anything we can do to get over this?

I chatted to nutritionist Claire Turnbull about this issue. It's one she says she and her colleagues see very often with their clients.

"This is why a lot of dietitians and nutritionists really try to discourage weight-focused goals", she says.

"Because when you're changing the way you eat, when you're changing your activity, the rate at which you lose weight won't necessarily be consistent. If you get caught up on the numbers, you get frustrated and it's more likely that you then sabotage yourself or think it's not worth it."

It is worth it, of course, to eat better and exercise more. But it's better, Turnbull says, for us to find other ways than weight to judge our progress: things like feeling better, sleeping better, having more energy, maybe going down a size or two in our clothes.

When we start dieting – particularly by cutting carbs – initial weight loss can be dramatic.

"People can lose weight quite quickly in the beginning, and then that can taper off," says Turnbull. "That's because carbohydrate in the body is stored with water, so when you drop your carbs back you get dramatic weight loss on the scales, but part of that is just that you're storing less water. That can only carry on for so long."

Another surprising thing to consider is that weight can plateau when we're not eating enough. "It's very common when people reach a weight-loss plateau to go, 'Oh, I'll eat a bit less, and a bit less, and a bit less", says Turnbull.

We can end up feeling we're eating hardly anything, but not losing weight: "It's because your body's gone into survival mode and said, 'hang on, there are not enough calories here'. Your body doesn't necessarily respond as you might expect if you cut the calories down too much. You can get to a point where your body is trying to 'help' you by maintaining your weight.

"When we get people to eat more regularly, eating lots of the lower-energy foods, lots of vegetables, just eating and telling your body there's food there, it gets it out of that starvation mode".

Turnbull recommends getting off the scales, since this can be really demotivating, and focusing on eating regular, decent-sized meals, with a good 10-12 hours overnight of not eating (keep an eye on the snacks and evening grazing).

Tweaking the exercise could help, too.

"A lot of people do cardio to burn calories. But the best way to boost your metabolism and get your body burning calories even when you're resting is to increase the amount of lean muscle you have on your body, which is where resistance training comes in."

Weight-bearing, resistance exercise not only builds and maintains muscle, but is good for bone strength as well, especially as we age.

Other things to look at include sleep – which can have quite an impact on weight – and stress. In other words, our health as a whole.

Bob's done well to lose the weight he has – evidence suggests losing even 5 per cent of your body weight, as he has done, is enough to lower your risk of cancer and diabetes and improve your heart health, sleep quality and energy levels.

Our weight naturally goes up and down, for lots of reasons, and natural variation is normal. We're better off focusing on other measures of success.

"When people are trying to get healthier", says Turnbull, "scales are not the answer".

Niki's fact check: Vitamin C can prevent and cure viruses

This one's been doing the rounds thanks to Covid-19, but there's scant evidence that vitamin C stops us getting a cold (another type of coronavirus), let alone this new virus.

The best science can say is that vitamin C can possibly reduce the duration of a cold by a day or so. We do need vitamin C, though, and having good levels in our bodies will help our immune system function as it should.

We can get the vitamin C we need from eating plenty of colourful vegetables and fruit, and without the potential side-effects of large doses of supplements. That's a far more enjoyable way to boost your immunity, too.