Your body undergoes many changes when you adopt a calorie-restricted diet. It uses its stores of energy to sustain you, which helps you lose weight. However, if you experience long-term feelings of fatigue while following a low-calorie diet, you need to change your intake or the types of food you consume. If your fatigue persists, speak with your doctor or nutritionist.
A low-calorie diet needs to provide enough calories to sustain you. Your diet should not dip below 1,500 calories if you are a woman of average stature. For men, this number is around 1,800 calories. Extremely restrictive diets may have you losing weight faster, but at a cost to your health and energy level. A sensible calorie-restricted diet supports losing between 1 and 2 lbs. per week. In some cases, doctors may prescribe an extremely restrictive diet for medical reasons. However, you only follow this type of diet for a week or two, and under the supervision of your doctor.
Low-calorie diets should have a transition phase in which you add more calories to maintain your healthy weight rather than lose weight. The American Heart Association recommends women consume between 1,600 and 2,400 calories per day, depending upon their age, height and level of activity. For men, the total daily intake should be between 2,000 and 3,000 calories. In general, you require less calories as you age, even if you do the same amount of exercise.
Types of Foods
Not all low-calorie diets feature foods that meet your basic nutritional requirements. Processed and packaged diet foods may have low calories but lack the fiber, vitamins and minerals that give you energy. If you feel tired while dieting, shift your diet to feature energizing foods. Berries, bananas, other fresh fruit, vegetables and leafy greens have high fiber, antioxidants and vitamins to sustain you. Eliminate nutrient-poor foods such as refined flour carbohydrates, sugary sweets and syrupy coffee drinks, juices and flavored waters. Eat whole grains such as amaranth, polenta, millet, oatmeal, whole wheat pasta and wild rice to provide energizing fiber.
Cutting calories is only part of the equation on a diet. To lose weight and feel more energetic, do daily activities that raise your heart rate. Not only do you burn calories, but you improve your cardiovascular health and establish long-term exercising habits that will ultimately help you maintain weight loss. Start with daily activities such as gardening, climbing stairs, walking the dog and playing in the park with your children. As you get more fit, add a brisk walk or jog and do yoga stretches to build strength.