Does HIIT burn more fat than walking or jogging?

Short answer

No. Across 40 trials, the difference in body-fat percentage was 0.77 points (about 0.5 kg for a 70 kg person), and fat mass itself didn't differ. The real advantage of intervals is that they take 40% less time.

Does HIIT burn more fat than walking or jogging?
'Short and hard → afterburn → much more fat loss' — does this formula hold?
Interval training, alternating all-out efforts with rest, is said to keep burning calories after the workout and strip more fat. We checked the research step by step to see whether it really beats steady exercise like walking or jogging.
Afterburn exists, but it's small
The extra burn after exercise is about 8-31 kcal
A review of 22 studies found extra energy used after exercise, within 3 hours, was about 136 kJ for intervals and about 101 kJ for steady exercise. Measured beyond 3 hours, it was 289 kJ versus 159 kJ. In calories, that gap is about 8-31 kcal.
In 13 trials, fat loss didn't differ
13 trials: no difference in fat mass or waist size
An analysis that pooled 13 trials (about 10 weeks, 3 sessions a week) found both intervals and steady exercise cut fat and waist size, with no difference between them. But intervals took about 40% less training time.
Pooling more trials showed a small gap
Body fat 0.77 points, about 0.5 kg for a 70 kg person
A 2024 analysis of 79 trials found that in the 40 trials directly comparing them, intervals cut body fat percentage 0.77 points more than steady exercise. For a 70 kg (154 lb) person, that's about 0.5 kg of fat. Fat in kg, belly fat around the organs and other measures showed no difference.
Even short sessions didn't fall behind
15-minute-or-less intervals didn't fall behind on fat loss
An analysis of 21 studies with 849 people found short interval sessions of 15 minutes or less used only 14-47% of the time of steady exercise, yet showed no difference on any measure, including fat. An analysis of 56 studies with 1,831 people found short intervals cut more belly fat around the organs.
Pooling only head-to-head trials said the same
Differences in fat and muscle were trivial
A 2021 analysis of randomized trials directly comparing intervals with steady exercise found trivial differences in both fat mass and lean mass (muscle and everything except fat), with high certainty. The researchers concluded the intensity pattern has minimal effect on fat change.
Bottom line: similar fat loss, less time with intervals
Choose by time and preference, not results
Intervals beat steady exercise by just 0.77 points of body fat percentage, with no difference in fat mass. Afterburn added about 8-31 kcal. Short on time? Intervals cut training time by 40%. If long walks suit you better, walking or jogging takes off fat about the same.