The fact that dieting is the number one predictor of weight gain is upsetting and difficult to absorb. Not only is dieting the only way you’ve been taught to be “healthy” and lose weight, but it is also assumed that if you fail at dieting, you are the problem.
Well, “failing” at dieting actually means your are biologically and psychologically normal, and that your body is working just as it was intended to. Wait, what? Let’s unpack this by going way back to where and how our bodies came to be.
I just love evolution. There is so much we can learn from our ancestors to explain and understand our modern-day bodies. When you think of evolution and how it relates to nutrition, I’m sure you recall when the Paleo diet came on the scene. To be honest, the Paleo Diet never made sense to me. (I mean, no diet makes sense, ever), but the idea that we should “eat just like our ancestors” is misguided, narrow minded and completely ignorant to the fact that:
1. Our bodies have evolved since that time (bigger brains, larger bodies = increased energy demand).
2. We live longer (sure, paleolithic people only ate unprocessed foods in small amounts – but this was before the industrial revolution and they also didn’t live past the age of 30).
3. Life is vastly different now and food availability is abundant (which, if you ask me, is a blessing and probably one of the reasons why our life expectancy is longer).
You can’t compare life as a homosapien to life as a modern day human. In our modern world, eating like our ancestors would mean limited food choices, a high potential for eating less than our bodies need and short life expectancy. Most people don’t acknowledge that weight loss and malnutrition is, and has always been, a major threat to life, which is why our bodies developed brilliant metabolic shifts to slow down weight loss and help us live longer. This weight regulation system remains embedded in our biological blueprint and offers a profound explanation for why our modern day bodies are good at gaining weight, and not so good at losing it.
Close your eyes and imagine you’re living in the Paleolithic era. Food is scarce, there are no grocery stores, pizza joints or fast food restaurants on every corner (you also have no idea what a corner is because you haven’t met “roads” yet). You see nothing but grass, snow or desert. You have no reliable timeline for when your next meal is going to be. Keeping your body fed means spearing down the first animal you see or walking miles to gather up tiny nuts and wild fruits with your bare hands. Though food is scarce, you have to make sure you have enough energy to have sex and reproduce so you can keep your bloodline going. You’re naked, afraid and quite possibly sunburned.
You might be wondering how the heck these people lived past birth. I know, it’s WILD. While there are many incredible proponents to explain natural selection and why we have surpassed all other animals on the evolutionary train – the stress response, bipedalism, opposable thumbs, brain development, language – metabolic changes that regulated weight was a huge saving grace to the Paleolithic body.
To make sense of this, a key piece of understanding is to realize that your desire to lose weight is antagonist to your body’s desire to keep you alive. Modern humans see weight gain as a betrayal by the body – something that is “wrong” or unhealthy. We view food cravings as something to be curbed or suppressed. But from the perspective our biology:
1. The drive for food (hunger) and motivation to eat (appetite/cravings) is what helps us survive.
2. Weight gain is a protective adaptation in response to famine, unintentional weight loss and death.
I would say, the opposite of betrayal!
If your Paleolithic body couldn’t find food for days, or even an entire week at a time, you would thank your body for learning how to store fat and slow energy burn. If not, you’d die faster. Malnutrition is a greater threat to life than weight gain is. In a way, survival of the fittest actually meant survival of the fattest (plot twist).
Here are some of the ways your body protects you from starvation*. I like to call them your starvation defenses. When calorie intake falls below what’s required to meet your metabolic demand (paleolithic day famine, modern day dieting), your body does the following things:
1. Break down muscle tissue to supply a quick usable form of glucose.
2. Increase fat storage** at your next meal so you have a rich savings account the next time food is scarce.
3. Slow down metabolism and conserve more energy by burning less.
4. Communicate with your brain to crave food and motivate you to eat – especially carbohydrates.
5. Increase set point weight*** – i.e make normal weight higher so the next time you don’t eat for a week you are more protected.
This is the reason why many keto dieters end up regaining weight and then some. Keto IS a starvation diet. (HARD STOP).
For a lot of chronic dieters who fight hard to shrink their bodies, these starvation defenses are being turned on regularly. Though you interpret weight gain and food cravings as “symptoms” of your OWN failure at dieting, in reality, they are very normal responses to under eating and food insecurity. From the perspective of your evolved human body, these starvation defenses are actually doing you a solid. Your biology interprets going above a certain weight as protective of life, and going below a certain weight is a threat to life.
Our bodies have not yet evolved to reverse these mechanisms or differentiate between intended calorie restriction vs unintended calorie restriction. Your body has no idea that you want to lose weight. It also probably would be horrified if it found out you were intentionally limiting food (how could you?!) Your body also don’t know that there are restaurants on every corner and grocery stores stocked with a variety of fresh produce and thousands of food products. It has no idea that access to food is any different now vs it was back then. It also can’t be bothered that body standards are ever changing and that our society values the thin body. It still thinks your naked, afraid and picking wild fruits out of the ground!
It is also important to acknowledge that over time, genetic evolution increased our natural body size and now that food insecurity and running from predators are no longer a threat, we have space to seek out pleasure from eating, which I think is a wonderful gift.
This is why dieting and weight loss is such a tireless pursuit and ends in failure 95% of the time. It is also why people who suffer from disordered eating and malnutrition often lose their sex drive and no longer menstruate.
Hunger is primal. Reproduction is primal. A starved body is not fit for reproduction. A starved body cannot survive.
Let’s serve up a big R-E-S-P-E-C-T for our bodies!
Post Scripts * Starvation doesn’t only mean NO food. It also means inadequate food. Similarly, dieting doesn’t only refer to a rigid meal plan, but also diet-like behaviors such as skipping meals, avoiding entire food groups, trying to curb appetite with low calorie foods or beverages and see-sawing between under eating and over eating. These are all behaviors that aim at fighting biology that turn on starvation defenses.
**Unlike carbohydrate storage, fat storage is unlimited, and it was intended to be that way. Fat storage is unlimited and provides more calorie/gm than carbohydrates. For this reason, fat is seen as very valuable nutrient “money”.
*** Your set point weight is the natural weight range at which your body is most comfortable. It can healthfully range anywhere from 5-10 lb.
