Exercising and Fat loss
Weight loss or weight gain is determined by the number of calories a person consumes, and weight or fat loss is determined by the type of activities a person does!
Fatloss is primarily driven by a calorie deficit, combined with sufficient protein, rest, recovery, and training.
Exercise gives a stimulus to the body to keep the muscles intact, or in some cases grow while on a deficit. The human body is inclined towards gaining and storing fats because of evolution.
While in a deficit, the body tries to save the fat mass, and without proper training, the body can end up losing muscles, with some fats.
To limit the loss, exercise is crucial.
The other benefit is PAL, physical activity levels.
They contribute a major chunk to the TDEE, exercising help with extra energy expenditure, which can help you stay away from starvation and you can create a deficit from a much higher number.
Long-term, low-intensity aerobic activities are primarily preferred as exercises that can help burn more energy. Like walking, jogging, and swimming.
For retaining as many muscles as possible, weight training is a must. It can be bodyweight training, or by using any available pieces of equipment.
The crux of this is, fat loss or muscle gain, health or weight maintenance, exercise is a must. The human body has evolved to such a point that it starts Saving fats as soon as it starts getting extra energy. To counter that, indulging in any kind of activity, (IMO, Weight training, and any long-term aerobic movement) can help you stay healthy, maintain a healthy fat percentage, and stay away from the majority of the lifestyle disorders. PS ( a combination of nutrition and training is required to get all the benefits)