Does losing weight slowly mean less rebound?

Short answer

No. Two groups that aimed to lose 15% over 12 weeks or 36 weeks regained 70.5% and 71.2% of the lost weight about 3 years later: no difference. People who lost weight faster at the start actually reached the goal more often and were still lighter years later.

Does losing weight slowly mean less rebound?
'Weight lost slowly stays off' — true?
It is common diet wisdom that weight has to come off slowly or it will come back. We checked studies that compared how much weight came back in people who lost the same amount quickly or slowly.
The same 15% in 12 weeks vs 36 weeks
About 3 years later, 70.5% and 71.2% came back
200 people were split up to lose 15% of their body weight over either 12 weeks or 36 weeks. Those who lost 12.5% or more were followed for 144 weeks (about 3 years): the fast group regained 70.5% of the lost weight and the slow group 71.2%, no difference.
More of the fast group reached the goal
81% vs 50%
In the same study, 81% of the fast 12-week group lost 12.5% or more in the set time, versus 50% of the slow 36-week group. Half of the slow group never got close to the goal.
Another study found the same
5 kg and 4.2 kg regained after 9 months
57 people lost a similar amount (9.0 kg and 8.2 kg) on either 500 kcal a day for 5 weeks or 1,250 kcal a day for 12 weeks. After 9 months, the fast group had regained 4.5 kg and the slow group 4.2 kg: no difference. A review of 13 studies where the same amount was lost at different speeds also found regain 9 to 33 months later did not depend on speed.
Flip side: those who lost fast in the first month
Were still lighter 18 months later
When 262 people were grouped by first-month speed, those losing 0.68 kg or more a week were down 10.9 kg at 18 months, versus 3.7 kg for those losing under 0.23 kg a week. Regain between months 6 and 18 was 2.6 kg vs 1.3 kg: no difference. The fast group was 5.1 times more likely to be down 10% or more at 18 months.
2,290 people followed for 8 years
Those who lost over 6% in the first 2 months stayed ahead
In 2,290 people in a lifestyle program, those who lost over 6% in the first 2 months, compared with those who lost under 3%, had 3.85 times the odds of being down 5% or more at 4 years and 2.28 times at 8 years.
Bottom line: losing slowly did not mean less rebound
The share regained had nothing to do with speed
When the same amount was lost, the share regained about 3 years later was 70.5% vs 71.2%, whether it took 12 weeks or 36: no difference. People who lost faster at the start reached the goal more often and were still lighter years later. Pick the pace you can keep up.