Summary

Summary

• A healthy weight brings large health benefits, and even a small loss helps. Losing just the first 5-10% of excess weight lowers the risk of Type 2 diabetes, heart disease, stroke and obesity-related cancers.
• Body composition can be assessed several ways - BMI, waist-to-hip ratio, girth measurements, skinfold callipers, bioelectrical impedance analysis and gold-standard hydrostatic weighing.
• BMI (Quetelet's Index) = weight (kg) / [height (m)]^2. A BMI of 30 or more indicates obesity; the bands run from underweight (< 18.5) and normal (18.5-24.9) through overweight (25.0-29.9) to Grade I, II and III obesity. BMI cannot distinguish fat from muscle, so it is less accurate for the very muscular and for pregnant women.
• Central obesity is defined by a waist over 102 cm (men) or 88 cm (women), a WHR over 1.0 (men) or 0.85 (women), or body fat above 25% (men) or 32% (women).
• Weight control is an energy-balance act. Aim to lose 1-2 kg a week through a negative energy balance of 500-1000 kcal per day (giving 500 g - 1 kg loss per week), combining caloric restriction with moderate, mainly aerobic, exercise. Fifteen practical diet modifications support this.
• Dieting alone has real pitfalls - very-low-calorie diets are hard to sustain, push the body into metabolism-slowing "starvation mode", and cause quick regain; fad and quick-fix diets are impractical and cause nutrient deficiencies. Regular exercise plus good eating habits work better.
• Food intolerance is a non-allergic, non-IgE food hypersensitivity, distinct from a food allergy. Types include enzyme absence (lactose intolerance), chemical causes (amines, caffeine), food-poisoning toxins (aflatoxins), salicylates, gluten intolerance and food-additive intolerance (nitrates, MSG, colourings); it is diagnosed with a food diary and exclusion diet and treated by avoidance.
• Common food myths about carbohydrates, oils versus ghee, apples/brinjals and iron, milk after fish, and water with meals are corrected by looking at the science.
• Diet is central to sport. It aids repair and recovery, shapes body composition, times fuel around competition, supports fitness/weight goals, provides ergogenic aids, maintains hydration, and enhances training adaptations. …