Q.Point out the pit falls of dieting

Dieting on calorie restriction alone runs into both a willpower problem and a biological one. …

The textbook states that while a calorie deficit always leads to weight loss in principle, dieting ALONE (without exercise) has a sustainability problem — sacrificing enough to sustain a very low-calorie intake for a long period is "too much for most people to handle," so most people eventually break down and return to old habits, causing the weight to return quickly. Separately, the body's own metabolic response works against drastic dieting: a sudden, drastic calorie cut pushes the body into 'starvation mode' — slowed metabolic processes that protect against a perceived long famine — which drastically cuts the body's energy requirement and stops weight loss even while eating very little. Fad or 'quick-fix' diets that cut out entire food groups (carbohydrates or fat entirely) are impractical, unhealthy, and cause deficiencies in other nutrients; special shakes/meals/programmes are expensive and impra …