How Much to Eat?
If you've ever searched the internet for "weight loss diet," "how to lose belly fat," "diet for women," or anything related to changing your body's size, you may have come across what is prevalent but extremely harmful advice. Your circle of friends or search results suggest that you shouldn't eat more than 1200 calories (especially if you're a woman) if you dream of fitting into your jeans again from your first year of college, the time before you had babies, or before going through menopause.
Any experienced and educated dietitian, nutritionist, personal trainer, or medical professional will likely advise you to eat significantly more than that, even if weight loss is your goal. Not only is 1200 calories enough for a small child, but it's not sustainable and detrimental to your health and metabolism if you manage to stick to the limit long enough. Additionally, this broadly accepted number is misleading because it insinuates that every woman has the same metabolic rate, which is incredibly false. Various factors, including gender, age, height, weight, lean body mass, and genetics, determine an individual's metabolic rate. In other words, if everyone ate the same, no one would look the same or get the same results, so eating the caloric intake your friend eats will not work for you.
Before explaining why 1200 calories will ruin your long-term success and quality of life, I'll explain everything that makes up the "calories out" part of the calories in vs. calories out equation. BMR + NEAT + EA + TEF equals the calories your body burns on average. Basal metabolic rate (BMR) is the amount of calories your body burns to keep your body on and functioning. NEAT stands for non-exercise activity thermogenesis, or all the movement you do in a day that is not intentional exercise. Which means EA stands for exercise activity. And lastly, TEF is the thermic effect of food which represents the energy it costs to extract energy from the food you eat. All of these individual values are determined by several things as well.
The body likes to be in a state of homeostasis, "a dynamic process that can change internal conditions as required to survive external challenges." If you change your caloric intake, the body will react and find a way to maintain it by adapting. So, if you begin your weight loss journey by eating 1200 calories, you will probably get results very fast. However, you will also hit a wall at the same rate or sooner. You will eventually hit a plateau which means your body has adapted to the new caloric intake vs. its output, and you won't drop any more weight unless you make another change. You can increase your exercise activity or reduce your caloric intake some more. However, suppose you reduce your calories below 1200. In that case, you risk undernourishing your body (if you haven't already) and being restricted to two or three small meals daily with no snacks or room for flexibility with your diet. Diets should consider short and long-term sustainability for better adherence and enjoyment of life.
The second reason 1200 calories is not sustainable is that you may hit your goal weight or physique that you wish to keep for a long time by the time you plateau, but that means anything above 1200 calories will cause you to gain weight in the long term. This does not mean that one day you might eat 2000 calories and all of your progress will vanish, but it does mean that you will have a very restrictive lifestyle if you want to maintain your weight. To put it into perspective, a single dinner out may contain 1000-2000 calories. A calamari appetizer, warm bread and oil, a pasta main, a glass of wine, and a dessert is a typical dining experience. Do this consistently year round as most people who enjoy food, travel, or socializing do, and you will slowly return to the weight you began with or higher.
With all this considered, the goal should be to lose or maintain your weight or physique on as many calories as possible. This will make your life during a diet phase easier, life after more enjoyable, and the following fat loss phase even less restrictive (if you wish to "cut" again). There are a few ways to do this, but it will take time and effort, like all great things. Self-educating (I highly recommend Layne Notorn's book Fat Loss Forever as a start) or working with a knowledgeable coach is a great way to begin!
