How many calories should I eat?
This is an important question if you are trying to lose weight or maintain your weight after losing a substantial amount of weight. If you have lost weight quickly, for example, using Total Diet Replacement (TDR) you will need to adjust your intake after Refeeding to suit your new smaller and lighter body.
Dieting does not change your metabolic rate. Dieting makes your body smaller and lighter and so it needs less energy to run, like changing from a big car to a smaller car. When you lose weight, you need to eat less than before as you are no longer supporting such a large body. On the plus side, you are now not as well insulated, as you have less fat coverage, so you use a little more energy to keep your body temperature up. Also, a smaller body is better able to exercise and so you are likely to move a little more and you are probably more active and better able to move quicker, which uses more energy.
Also, a smaller body is better able to exercise and you are probably more active. Therefore, you are likely to move a little more and better able to move quicker, which uses more energy.
The easiest way to estimate how many calories you should eat is to enter your details in our B.M.I. calculator. This calculation also estimates your Total Daily Energy Expenditure (T.D.E.E.) and the amount of calories it takes to maintain your weight.
Calculating your T.D.E.E. is also useful if you want to estimate how many calories you are consuming before you lose weight. Most people underestimate their daily calorie intake. One of the interesting experiences when patients are on Total Diet Replacement or Meal Replacement is that people realise just how many calories they are consuming from poor eating habits and choices.
When you have finished dieting and reach your target weight you should recalculate your T.D.E.E. to give yourself a rough measure of how many calories it takes to maintain your new lower weight.
T.D.E.E. is much more useful than metabolic rate calculations as it takes into account individual lifestyle factors. The factors are your height, age, gender, weight and level of activity.
Let us take each factor in turn ;
- Height - taller people use more calories
- Age - generally younger adults use more energy and energy usage falls as we age
- Gender – males have a higher muscle mass than females and use more calories than women
- Weight - a bigger body uses more calories to move around than a smaller body
- Level of physical activity – exercise does not use as many extra calories as you might think. Running a mile only uses about 100 Calories. However, regular exercise does have many health benefits and builds your overall daily energy usage which helps with weight maintenance.
- Environment - people who work or live in colder environments use more energy maintaining their body temperature. Turning the heating down 1 or 2 degrees and dressing more lightly helps increase your energy use and weight maintenance.
In summary, humans are a closed system. If we put more calories into our bodies than we are using, we will gain weight. If we put less calories in, for example by dieting, we will lose weight.