Calories and hormones: BFFs
What we have been told for most of our lives is that a calorie is a calorie is a calorie. Calories, and calories alone, are what matters at the end of the day. Energy in and energy out. Take in the same calories you burn and you stay the same weight. Eat more calories than you burn and you gain weight, eat fewer and you lose weight. Doesn’t it seem so simple? Yet it just doesn’t seem to add up that easily, particularly for the millions of people throughout the world that are trying to change their weight. Why? There’s a pretty big problem with this “equation”- it is anywhere from slightly misguided to completely misleading. On the surface it holds some truth (our body does regulate energy intake and output) but when we look at the dynamic, adaptable and intelligent human body we often find that we can’t ever think things are that simple. We must always take a step back and consider the whole picture: calories are not a one man show.
Why? Because calories have a best buddy when it comes to the body: hormones. Calories do count to a degree but only influence half of the equation. The other half, and the half that really runs the show, are hormones. Hormones are the ultimate regulator of weight and energy balance and what you eat influences your hormones, plain and simple. Calories can do 1 of 3 things: stimulate normal hormonal functioning and encourage weight maintenance, stimulate energy storage hormones that results in weight gain or stimulate hormones that release energy and end up in weight loss.
Many hormones influence weight, including thyroid, testosterone, estrogen, glucagon, cortisol, leptin and insulin. Every single one of these contribute to the body storing energy or releasing energy in a major way. Every single one of these actions are influenced by the amount and type of calories we eat (there are many intricacies to the hormonal/calorie connection and this post is simply looking at the basics of the relationship although many details and exceptions exist and impact our bodies).
**Takeaway #1: The calories you eat tell your hormones and body what to do.**
An Apple vs. Soda vs. Steak vs. Macadamia Nuts
Whenever someone (including experts in the field of nutrition, health or medicine) claims it’s all about the calories, think of this example. Take 100 calories of each of these foods. Each has the exact same calorie/energy content but will have a different impact on the body. Each food has different nutrients and tells your body, specifically hormones, how to deal with the energy it provides. It should be a pretty easy mental exercise to imagine eating 2000 calories a day from just apples, soda, meat or nuts would end up in differing results. I challenge anyone who believes in the calorie hypothesis to drink nothing but soda for a while and tell me if elicits the same body composition results as just eating apples, meat or nuts for the same period of time. The same caloric intake can impact our metabolism vastly differently because of how these calories influence hormones.
How exactly these and other foods impact your hormones comes down to a few main points, primarily the macronutrient source of the calories (i.e. fat, protein, carbohydrate) and the subsequent effect on insulin. Calories are a form of both energy and structure, which is why the impact on the body is different depending on the macronutrient content. Carbohydrate calories are energy calories, while both protein and fat calories fill structural roles as well as energy needs. Carbohydrates enter the body as energy and are either used or stored in muscles, organs or fat. Proteins enter the body and are used mainly for tissue structure but can also be used as energy or stored. Fat enters the body and can be as structure, used as energy or stored as fat (a bit goes to muscles).
The main determinant of how the body uses each type of calorie is its impact on insulin. Insulin is a building hormone, meaning it builds tissue. Whether muscle, organ or fat, insulin brings resources, usually glucose, to make cells grow. It is a vital part of human function and we have a hard time surviving and thriving without it. Insulin does become a problem when we produce too much in response to excessive energy intake. When we take in energy and the body’s muscle, organ and energy systems don’t need any more, insulin steps up to get the energy out of the blood and into more useful storage. Fat is next in line and is happy to provide plenty of storage for a rainy day, extended fast or seasonal famine. In the natural world of human existence, this insulin dynamic enabled us to make it through some harsh conditions. Now, this almighty hormone can cause us to buy bigger clothes pretty quickly.
**Takeaway #2: Insulin delivers and stores energy (which can be good or bad) and when it’s in your system, energy release (fat burning) slows or stops.**
What impact do different calories have on insulin?
Carbohydrates have the biggest impact as they get digested into simple sugars and enter the blood stream the most rapidly and typically cause a substantial release of insulin to get that energy put into use. If your muscles and organs need a bit of energy or have been depleted from either activity or fasting, insulin transports some sugar there. The rest gets used as daily activity energy or stored as fat. What happens if we don’t need much energy? The fat cells keep on taking that excess energy.
Protein elicits a smaller insulin response and gets shuttled off into cellular repair and tissue building, with a just touch of it getting used as energy. Insulin helps with this transport but much less is needed per calorie.
Fat causes almost no insulin release. These calories get digested slowly, then are shuttled off to be used for structure, burned as energy or stored for later use. When little or no insulin is circulating, little fat gets stored as fat and more gets used as energy.
An additional caloric source, alcohol, is treated a bit differently by the body but still influences hormones greatly and will be covered separately in another post.
**Takeaway #3: Carbs elicit the most insulin to be released, protein a moderate amount and fat virtually none. Calories that drive insulin release can encourage energy storage, calories that don’t require much insulin allow more energy release to occur.**
Typically, the higher your carbohydrate intake, the more insulin you release to shuttle it around. This can be a major problem if your activity levels are low and that energy doesn’t get used for muscles and organs. Energy intake that drives insulin but exceeds the need of the body ends up in excess storage. Although carbohydrates in general stimulate more energy storage than their protein and fat counterparts, they are not alone in driving negative hormone response. Processed foods (think man made, boxed, bagged, prepared meals, etc.) digest much quicker despite their macronutrient breakdown, enter the blood stream faster and stimulate more insulin release. As a general rule, processed food also contain higher amounts of carbohydrates, lower amounts of fiber and are easily over eaten. All of these end up in insulin, energy storage and fat staying locked in your fat cells.
On the contrary, food in its natural state, such as meat, fish, vegetables, fruit, nuts, seeds and other one ingredient foods have less negative hormonal impact, both in insulin and other hormones.
What else plays a role in the calorie/hormone connection?
In general, this write up I have started has only scratched the surface. The list of how calories are connected to hormones is very extensive and actually will need some additional posts to continue the discussion. In terms of the calorie side, the amount of fiber, vitamins, minerals and when you eat different calories also play a role in how your hormones react to them. On the hormone side, all of the above listed hormones (thyroid, testosterone, estrogen, glucagon, cortisol, leptin) are influenced by the kind of calories we eat and deserve some explanation as well. Even other food categories, such as alcohol and dairy, have different properties that make them influence the body in a different way. Stay tuned for more thoughts on each of these categories.
Since this simple little post turned into something quite lengthy and is starting to lean toward too long and detailed it’s time to wrap it up for now. We only covered the simple relationship here but getting the concept of calories and hormones established and understanding the basics of insulin is an important keystone and helps encourage the body toward leanness and managed energy usage.
The Bare 5 Bottom Line on Calories:
1. Calories matter in terms of energy but matter more in the context of hormones. Calories are a stimulus to which hormones respond and control weight regulation.
2. Some kinds of calories promote hormones that keep us slim and strong, others turn up fat storing hormones.
3. Carbohydrates, particularly in excess, stimulate insulin release and promote energy storage. Fats and proteins can stimulate this process but in a much less impacting way.
4. Eating man made, processed, food products will promote hormones that encourage the purifier version of you. Eating natural, whole, real food will promote a hormonal environment that encourages the lean version of your natural body type.
5. The impact of these calories on your hormones and weight regulation changes from day to day and is influenced by many things, particularly stress, but these two will always be BFFs.
Thanks for reading, have a great calorie and hormone filled day!
P.S. I don’t think that calories don’t matter because they certainly do to a degree. I simply think we need to look a little deeper because both science and common sense tells us that the signals that calories send our body is more impactful than the sheer number of calories a food has.