Why Cutting Calories Doesn't Work
There are many diets out there on the internet and in shoddy celebrity cookbooks that promote radical, extreme, and sometimes a bit bizarre eating habits. They all promise to give you what you've been looking for: great body! Tons of energy! Clear skin! Righteousness and a great future! (wait, what?) But most cannot and do not deliver.
Many of you may know my opinions on fad diets or extreme ways of approaching eating. Some of you may not, but let me sum it up: I don't believe in any of them. If you want to try to eat healthy, you've got to come to fundamental understanding, and even me saying it now probably won't be enough for many to truly believe: There are no quick fixes. There is no magic diet. There is no magic secret that celebrity fitness trainers have that you do not. There is only eating well, consistency, and dedication. Many people don't understand it when other people tell it to them (trust me, I'm there with ya!), so you'll likely have to come to this on your own...Nevertheless, I'd like to save you some trouble if I can! So allow me to address one topic that I am passionate about: cutting calories. Should you do it? How many calories should I eat? So-and-so eats 1200 calories and is fit, so should I do the same?
The answer is simple: no. Don't drastically and suddenly cut calories and then keep them down for long periods of time. Quick-fix diets don't work, and neither does deprivation. In fact, I never advocate following word-for-word someone else's diet. What works for them might not work for you. Just taking a quick tour through the internet will reveal 101 diets that different people follow, and how it is a miracle for them and works wonderfully--but it might work for them and not for you. You cannot blindly follow someone else--especially just random fitness "experts" who follow some crazy extreme diet! Do not eat only bananas or only high-protein foods!
Moreover, if you focus on calorie-counting and slashing your calories dramatically, you might become dangerously obsessed with food and dieting, that you develop unhealthy behaviors and attitudes towards food that you can't shake even after you've already resumed eating normally again. In fact, this was proven in the Minnesota Starvation Experiment, where men who were deprived of food developed unhealthy eating behaviors. It's proven! Starving yourself voluntarily sets you up for all sorts of unhealthy, anxiety-filled behaviors.
The first reference: your BMR.
If you're wondering, however, how many calories you should eat in your hopefully well-balanced diet, let me first argue about why you should never cut calories below your BMR (or basal metabolic rate). Your BMR is the energy your body requires to run at its most basic level: if you simply laid in bed all day and didn't move or eat. It is roughly your weight in pounds times 10 (ie., so if you weigh 140 lbs, your BMR is approximately 1400). This is not a scientifically proven rule, and does not apply to everyone, merely a rough estimate. And it assumes that your thyroid and metabolism is working normally.
What happens to your body when you drastically cut calories?
Ok, so if you do cut your calorie intake below your BMR, this is classified as "starvation" diet. When your body goes into starvation mode, this is what happens. (Heads up, ~science~ is coming your way!)
So first, when your body perceives you are in "stress" (ie., short-term), your body releases growth hormone (which is responsible for growth, maturation, protein synthesis, and helping control your blood sugar), as well as increasing cortisol (your "stress hormone"), and epinephrine (the fight-or-flight hormone), among others. These hormones are responsible for maintaing your blood sugar by breaking down fat for energy--but ALSO breaking down muscle! With no discrimination! They don't care that you're heading to the gym and trying to get lean and turn that muscle into fat. In the short term, the effects aren't too crazy; they work to keep you from hypoglycemia (low blood sugar) symptoms like fatigue and drowsiness.
In the long-term however, your body adapts to this constant low-level stress and decreases growth hormone synthesis, though cortisol stays chronically elevated. This promotes elevated blood pressure, redistribution of body fat to your middle, and muscle wasting. In addition, your body decreases thyroid hormone output. Thyroid hormone is responsible for maintaining a normal BMR, so when this function goes down, so does your BMR. Your body adapts to a lower energy intake, and thus your metabolism is chronically disrupted and re-adjusted. In addition, you're losing all your hard-won muscle, which also negatively impacts your BMR because having more muscle means having a higher BMR as it requires more calories to maintain than adipose tissue (fat). In addition, your training sessions won't be going as well, so it will disrupt your fitness routines and goals!
Soooo when you start increasing your calories again, what happens? You gain fat, even if you are still not eating a lot, and even eating healthy! Boooo. Your thyroid is still putting out lower levels of thyroid hormone than before when you were in "stress", and it takes time for your body to readjust again.
Yay! Science over! (For now...)
So what should you do instead?
Ok so this doesn't sound like fun. You don't want to get caught in this trap. What should you do to avoid this hard-to-escape situation?
Don't crash diet! And if you have in the past, increase your calories slowly (perhaps 100-200 per day every week, depending on how much you cut down), until you are back to normal. This doesn't mean adding in unhealthy foods. Don't add those calories back in as ice cream and fries, add back in healthy fats like walnuts, complex carbs like sweet potatoes, and veggies, veggies, veggies! In addition, watch your fitness routine. Back down on long cardio sessions (which is a longer stressing session that raises cortisol), go for shorter sessions like brisk walking, HIIT, and weight-lifting instead to help revive your metabolism.
Ok, so how many calories should you eat (if you need a number)? I recommend using this calculator, and filling it out honestly.
But do you really want to count calories forever? Probably, no. And I hear you, cause that sucks. So what I suggest is counting calories with an app like My Fitness Pal for 1 week to see how much you generally eat on a day-to-day basis. If you are significantly above or below (around 300 calories) what the calculator recommends, try to adjust and count calories until you find out around what your recommended intake feels like. If you eat what they recommend and still feel hungry, take an inventory of your diet. Are you eating a lot of simple carbs and sugar? These will not fill you up, and can even mess up your sense of hunger as they can lead to unhealthy cravings. However, if you are focusing on high-fiber/protein/nutrient foods, then guess what? Eat more! Be mindful and eat until you are satisfied! Listen to your body, be mindful, and that alone should be your guide, not calories.
Now that you know about how much you should eat, now what should you eat? Each meal you eat (whether you choose to eat 3 meals, or 5 smaller ones) should include roughly this formula:
50% non-starchy veggies + 20% protein + 20% carbs + 10% healthy fat
Again, this is just a rough formula, not a hard-and-fast rule. An example of this might be 2 cups of raw kale, topped with 1/2 C lentils, 1/2 small sweet potato, topped with 1 TB tahini + spices. A great way to get ideas on how to build meals is buddha bowls! (Look out for a buddha bowl roundup in the very near future)
Here are some other ideas for balanced meal components:
- Spinach, kale, leafy greens
- Peppers, onions
- Summer squash (zucchini)
- Cauliflower, broccoli, brussel sprouts
- Beans (black, great northern, chickpeas)
- Hemp seeds
- Meat, if you choose to eat it
- Peas (though these also are a starchy veggie!)
Carbs (starchy veggies or grains):
- Sweet potato
- Peas, carrots
- Brown rice
- Brown rice/quinoa pasta
- Olive oil
- Nuts - walnuts, almonds, pecans
- Seeds - hemp, sesame, chia, flaxseed
- USDA calorie calculator
- Whole Foods Recipe Ideas
- Dr Hyman on Eating Less + Exercising More
- Minnesota Starvation Experiment (where grown men who underwent voluntary starvation developed unhealthy obsessions with food)
- Constanzo Textbook of Physiology (where I learned all of the science-y stuff I reviewed above!)