Weight loss occurs when the body is expending more energy in work and metabolism than it is absorbing from food or other nutrients. It will then use stored reserves from fat or muscle, gradually leading to weight loss. For athletes seeking to improve performance or to meet required weight classification for participation in a sport, it is not uncommon to seek additional weight loss even if they are already at their ideal body weight. Others may be driven to lose weight to achieve an appearance they consider more attractive. However, being underweight is associated with health risks such as difficulty fighting off infection, osteoporosis, decreased muscle strength, trouble regulating body temperature and even increased risk of death.
The body doesn't react to all fats in the same way. Research correlates high intake of saturated fat (the kind in meat and dairy) to increased visceral fat, says Patton. On the other hand, monounsaturated fats (the kind in olive oil and avocados) and specific types of polyunsaturated fats (mainly omega-3s, found in walnuts, sunflower seeds, and fatty fish like salmon) have anti-inflammatory effects in the body, and if eaten in proper portions may do your body good. But Patton warns that eating too much fat of any kind increases your calorie intake and could lead to weight gain, so enjoy healthy fats in moderation.
Chloe Madeley is a Level 2 Gym Instructor and Level 3 Personal Trainer with an Active IQ nutrition qualification. She has been an active personal trainer since 2013, helping both men and women achieve their body transformation goals in London gyms, parks and even online. She is the author of the popular health and fitness blog FitnessFondue.com and has two best-selling apps (15 Minute Fat Loss and Weights 4 Women) and is the best-selling author of The 4-Week Body Blitz and The Fat-Loss Blitz.
Carb crazy? Consider this: Refined carbohydrates, such as bread, potatoes and rice, create a surge in insulin that in turn drives down your resting metabolic rate, explains Aronne. "It's important to keep carbohydrates in your diet, but really focus on fruits, vegetables and whole grains, which have less of an effect on insulin levels," he explains. And when buying whole-grain breads and cereals, make sure the first ingredient listed is whole wheat, whole oat or cracked wheat.
Of all the foods you eat, the high-protein ones are the most important for losing fat. First, they keep you feeling full, which prevents overeating and needless snacking. Second, they boost your calorie burn throughout the day because protein takes more energy to digest than carbs or fat. Third, when accompanied with weight training, a high-protein diet prevents muscle loss that might otherwise happen when you suddenly cut calories.
The easiest way to cut calories? Eliminate excess dietary fat—meaning no butter, oils, or salad dressings (low-fat or fat-free dressings are OK); remove the skin from chicken; substitute egg whites for most of your whole eggs; avoid whole-milk dairy products; and ditch marbled red meats such as rib-eye for lean cuts such as flank. Keep some healthy fats in your diet, such as salmon, mixed nuts, peanut butter, and avocados.
This may explain why the fat-burning effects of eating more protein were confirmed in a study published in the American Journal of Physiology. One group was fed a high-protein diet (just over 1 gram per pound of body weight per day) while the second group consumed an amount closer to the lower recommendation of the RDA (recommended dietary allowance). The group eating the higher-protein diet burned the most fat.