evidence form obserational studies consistently demonstrates that habitual increased intake of fruits vegetables and whole grains is associated with lower body weight increase over time adherence to healthier dietary templates (including incorporation of higher amounts of plant-based foods) in intervention studies also tend to evidence greater weight loss than control diets this further highlights the importance of fruits vegetables and whole grains as the foundation of positive dietary habit in contrast randomised controlled trials based on increase of fruits vegetables or wholegrain food intake alone tend to show no impact on body weight or body fat outcomes suggesting either that the length of pervious studies is not long enough to observe measurable effects or that such dietary changes alone do not benefit these outcomes