Whole foods are great for fat loss because they allow you to eat satisfying volumes of food whilst obtaining more nutrition and fewer calories.
This is possible because whole foods typically contain more fibre, water and protein than the more heavily refined counterparts.
Fibre is the indigestible portion of plant foods and serves a number of useful purposes in our digestive tract. From a weight-loss perspective fibre provides bulk and volume to our meals without increasing caloric-load.
Typically whole foods contain a certain percentage of water. which will vary from food to food. Like fibre this adds bulk without adding calories.
Most whole foods contain some protein (albeit some more than others) which is a useful macronutrient for those looking to lose weight as it is known to promote satiety and reduce hunger which ultimately helps in eating less. Furthermore, along with resistance exercise, protein helps to maintain lean mass whilst running at a calorie deficit. This ensures the majority of weight loss stems from our fat stores not our muscle stores.