Hi Sriranjan,
A calorie deficit isn't always required for fat loss. Fat loss is dependent on a lot of factors.
Many studies have found that moderate intensity, long duration cardio such as walking and running are actually really inefficient for fat loss, which is what the meta analysis was showing. Short duration, high intensity efforts are much more effective for fat loss.
Matthew MacDonald wrote a good article for Elemental about the calorie myth: https://elemental.medium.com/the-calorie-myth-f9e5248daa0c
There is also a book called The Calorie Myth which addresses this common presumption that fat loss is about calories in vs calories out.
From the meta analysis cited:
"SIT resulted in a 91.83% higher reduction in body fat percentage than MICT (Moderate-intensity continuous training)."
