Your maintenance calories after a diet

Your new maintenance is lower than before the diet, about 10 calories a day less for every pound you lost, and sometimes a little lower again. Step up to it over one or two weeks, expect a pound or two of water, then correct it from your trend.

Should you go back to what you ate before?

People come off a diet in one of two ways. Some go straight back to what they ate before it, which was their maintenance at their old weight. Others have heard about reverse dieting, adding 50 or 100 calories a week for months to “repair” their metabolism.

The first group usually regains. Their old maintenance is too high for their new body. The second group spends months eating less than they need to, and often gives up on the way.

Then there’s the scare in between. You add 300 calories a day, the scale jumps 2 pounds in three days, and you decide you’re gaining fat and go back on the diet.

Why the scale jumps when you eat more

Glycogen, the sugar stored in your liver and muscles, is like a dry sponge at the end of a diet. When you eat more, especially more carbs, it soaks up water, three to four grams for every gram of glycogen, and the scale shows the extra water the same week.

In the ICECAP trial, resistance trained athletes who had dieted for three weeks then spent one week eating at maintenance. On average their weight went up by about 1.3 pounds (0.6 kg), their lean mass, which counts water and glycogen, went up by about 1.5 pounds (0.7 kg), and their fat didn’t change. Their resting burn also rose a little, from about 1,670 to 1,720 calories a day.

That jump happens once. After the sponge is full, the scale goes flat, and from then on it tells you whether your maintenance number is right.

How to work out your new maintenance

1. Look at the last four weeks of your diet. Find your average daily calories and your weekly rate of loss from the trend.
2. Add back the deficit. A pound a week is about 500 calories a day. If you ate 1,900 a day and lost 1.2 pounds a week, your maintenance is about 1,900 + 600 = 2,500.
3. Check it against a calculator. Run the maintenance calculator at your new weight. If it’s higher than your own number, trust your own.
4. Step up in one or two moves. Add half the gap in week one and the rest in week two.
5. Hold for three or four weeks. Then adjust by 100 to 200 calories if the trend is still moving.

Put most of the extra into foods that keep you full and train well, like protein, fruit, potatoes, rice and oats. Keep protein at your number from your calories, pace and protein.

Why your new number is lower than you’d think

Two things lower your maintenance after a diet, and the first is just size. NIH researchers worked out that each pound you lose lowers the calories you need by about 10 a day. Lose 30 pounds and your maintenance is about 300 calories lower than before.

The second is the body adapting, and how big it is depends on who you ask.

Both are probably right for their own people. The Columbia studies held people at a lower weight in a lab for weeks. The 2020 study measured women after they’d been eating at maintenance for a month. We’d plan for your new maintenance to be a little below what a calculator says, and let three or four weeks of trend decide.

Does reverse dieting work?

Reverse dieting means raising calories very slowly after a diet, often 50 to 100 a week, for months. The idea is to let your metabolism catch up so you don’t regain.

A 2014 review of metabolic adaptation in athletes described it as popular with physique athletes on the strength of their own experience, and found no studies testing it. The authors said it could only be judged on theory until someone tested it.

We’d step up faster. The adaptation that does exist is mostly about eating less and weighing less, and eating at maintenance starts to undo the first part within a week, as the ICECAP athletes showed. Months of eating below maintenance keeps the hunger and the low energy going for longer. If going up in two steps feels too scary, use three or four, but get to maintenance within a month.

Why coming off a hard diet slowly still makes sense

The one case for going slowly is a very hard diet. In the Minnesota Starvation Experiment of the 1940s, young men volunteers were put on a semistarvation diet for about six months. They lost about 25% of their weight, including about 70% of their fat and 27% of their lean mass.

When food came back, they overate for weeks. In a 1997 re-analysis of the records, Abdul Dulloo and his colleagues found that the overeating went on until lean mass had recovered, and by then they had regained more fat than they’d lost. Their bodies kept them hungry until the muscle came back, and fat came along for the ride.

The lesson is to keep as much muscle as you can during the diet, with protein and lifting, so there’s less to rebuild afterward. And if your diet was extreme, give the step-up a few weeks with structure, protein at every meal and a daily weigh-in.