The first few weeks went well. The scale was going down, your jeans were closing again. Then nothing. Three, four, five weeks on the same number, even though you have not let anything slip. The reflex is almost universal, eat even less. That is exactly what keeps the plateau going. Your body is not broken, it is defending itself, and once you understand the mechanism, you know what to do.
A real plateau, or water
First, check that it really is a plateau. Weight varies with water, salt, digestion and, for women, the cycle. A kilo more on the scale after two weeks of effort can be perfectly normal. Look at your belly, your energy and your sleep too. The quality of your weight matters as much as the number.
The four kinds of expenditure that drop together
Your daily energy expenditure breaks down into four parts. Resting metabolism accounts for 40 to 80% of the total. Activity outside exercise, known as NEAT, accounts for 5 to 30%. The thermic effect of food, what digestion costs, 8 to 15%. And exercise itself, from 0 to 30%.
When you lose weight, these four parts drop one after the other. You eat less, so you spend less on digestion. You are lighter, so every step and every session costs less, because there is less mass to move. If the restriction lasts, your resting metabolism falls, especially if you have lost muscle. And NEAT drops, often first. Researchers call this adaptive thermogenesis.
At Rockefeller University in New York, volunteers kept at a weight at least 10% below their usual weight burned 6 to 8 kcal less per kilo of lean mass every day (Leibel et al., 1995). For someone with 50 kg of lean mass, that is 300 to 400 kcal a day. The drop was split evenly between rest and movement. The same team found this drop in people who had held their weight loss for more than a year (Rosenbaum et al., 2008).
NEAT, the expenditure that fades without a sound
NEAT is everything you do that is not exercise. Walking, taking the stairs, pacing while on the phone. This share often weighs as much as your training, and almost nobody thinks about it.
We have known how much it matters since a study published in Science in 1999. Sixteen volunteers ate 1,000 kcal more than they needed for eight weeks. Two thirds of the rise in their expenditure came from NEAT, and it explained tenfold differences in fat storage between participants (Levine et al., 1999). The body raises it when it needs to spend, and lowers it when it needs to save.
Under restriction, that is what happens. In people who have been dieting for a long time, the sign is well known. They lean against tables, rest their elbows on the counter, sit down more often, without even noticing. In a six-month trial in Louisiana, everyday activity levels fell by the third month in those who only cut calories. They did not move in the group that combined a lighter restriction with exercise (Martin et al., 2007).
The only reliable measure you have is your step count. If your steps have melted away since the start of your diet, you have a good part of the explanation.
Why eating even less does not work
Faced with a plateau, most people cut even more calories. It is easy at first, but rarely sustainable. Resting metabolism falls with intake, NEAT follows, and you end up chasing your tail. Without enough protein or strength training, part of the weight lost is muscle, which lowers resting metabolism even further.
Betting everything on exercise works no better. The body can compensate by cutting NEAT that same day, by 300 to 500 kcal. Hence that feeling of killing yourself at the gym while the scale does not move.
Combine the levers instead of tightening the screw
What works is adding up small levers. In my guide Boost Your Metabolism, I take the example of a person who eats and burns 2,500 kcal and aims for a 500 kcal deficit, or 20%. Instead of taking it all off the plate, they add 200 kcal of exercise and a 15-minute walk at lunchtime, about 100 kcal. They cut 20 g of carbohydrates, or 80 kcal. They swap part of their fat for protein, which gains them about 45 kcal through the thermic effect, and they add omega-3s and a cup of green tea. In total, about 500 kcal, without ever feeling like they are on a diet.
That deficit means losing about 0.45 kg a week, an excellent pace for weight loss that lasts. Aim for 10 to 20% of your expenditure, towards the lower end if you are small-framed or in perimenopause.
Three 10-minute walks, morning, noon and evening, burn 200 to 300 kcal. A standing desk, alternating with sitting, burns another 100 to 200 a day. Added up over weeks, these crumbs weigh heavily.
Sleep, the forgotten lever
At the University of Chicago, ten overweight people followed the same 14-day diet twice, once sleeping 8.5 hours and once 5.5 hours. With less sleep, they lost 55% less fat and 60% more lean mass (Nedeltcheva et al., 2010). Same diet, different result. Lack of sleep also lowers NEAT and the urge to train. If your nights are short, that is where to start, before you touch your plate.
What I take from it
A plateau is not a failure. It is your body adapting to its new weight, as it is meant to. The answer is not to give it even less, but to give it reasons to spend. More steps, a little more muscle, longer nights. Your body knows how to adjust in both directions. It is up to you to show it which one.
This article is for information only and does not replace medical advice.