Imagine this, you are overhearing a conversation about weight loss. You hear the simplistic recommendation to start exercising more and cut down calories. We have all heard it: “Eat Less. Move More. It is really that simple.” Is it that simple, though? Sorta. Kinda. Not really. Let’s dive in.
A calorie is a unit used to measure energy. According to the first Law of Thermodynamics, a calorie is a calorie; this energy is neither created nor destroyed- just transformed. The human body is always transforming energy (i.e. calorie) to be used or stored. It can be used to perform daily tasks and keep your body humming, or it can be transformed for later use in the form of body fat or muscle.
For weight loss to work, a person must be in a caloric deficit. This is defined by burning more calories (calories out) than calories consumed and absorbed (calories in). Calories Out > Calories In = Weight Loss. On the contrary, when “calories out/burned” become less than “calories in,” weight gain occurs. When calories in = calories out, weight is maintained. So, technically, it really is that simple.
Here is where it gets dynamic and complicated:
- Truly determining how much one burns (calories out) and how much one consumes AND absorbs (calories in). Both sides of the equation have several factors that affect the final caloric number.
- Finding a sustainable approach that fits one’s lifestyle and can last PAST the weight loss phase (or else regain is more likely).
- Knowing what to do when metabolic adaptation and plateaus occur to prevent a reduced threshold for weigh gain long-term.
4 Factors Contributing to “Calories Out”
- Resting Metabolic Rate (RMR): Also known as our “metabolism.” This is how much the body burns while resting and is measured in calories (remember, calories are a unit of energy). The RMR makes up MOST of the calories on the “calories out/burned” side of the weight balance equation.
The factors affecting the RMR are
- Body size & body composition: more weight (aka mass) technically results in more calories burned due to increased RMR. When weight is equated, the person with more muscle is going to burn more calories than the person with more fat mass.
- Age: as one ages, RMR declines.
- Genetics: our origins matter and affect how the body functions.
- Dieting history: prolonged caloric deficits lower the metabolism, while reverse dieting helps to increase the metabolic rate over time. That is why it is super important to not be in a caloric deficit for too long and to utilize a reverse diet throughout the weight loss journey.
- Hormones: those with chronic conditions, such as hypothyroidism, will experience a lower RMR than normal. On the contrary, those with hyperthyroidism will experience a higher RMR than normal.
- Fevers increase RMR
- Sleep: poor sleep results in a slowed metabolism, while adequate sleep supports a healthy metabolism.
The list goes on, but this gives an idea of most common influences on the metabolism.
- Exercise Thermogenesis (ET): calories are burned via exercise. Type, duration, frequency, how well we are fed, and how well we slept can all influence this number. Cardio burns more calories in the hour when compared to resistance/strength training. However, strength training will increase lean muscle mass, which increases the metabolism (RMR) long-term. This is just another reason why having a balanced exercise regimen vs being a cardio queen is important.
- Non-Exercise Activity Thermogenesis (NEAT): calories are burned doing activities of daily living, such as grocery shopping, cleaning, walking to the mailbox, and chasing children around.
- Thermogenic Effect of Food (TEF): how much energy (calories) are required to metabolize, digest, and absorb the food eaten. This is influenced by food quality and macronutrient (carbs, proteins, fats) composition. For example, someone who eats 1700 calories but has balance between the proteins, carbs, and fats will burn more calories than the same someone who eats 1700 calories of just carbs and fats. Why? Because protein has a high thermogenic effect of food (30%), meaning it takes 30% of those calories for our bodies to process protein. Whereas fats and carbs are much less (4-10%). Someone who eats mostly whole, minimally processed foods is going to have a higher TEF than the same someone who eats mostly highly processed and refined foods. Whole, minimally processed foods have a higher TEF than highly processed and refined foods.
4 Factors Contributing to “Calories In”
Why do these factors even matter? Just don’t eat too much and all is well. Except it is not that easy. We must address these factors because these influence the way we approach the nutrient goals (i.e. a caloric deficit for weight loss). A nutritional plan should be sustainable and lifelong. It should consider culture, lifestyle, schedule, medical conditions, mood, and much more. We look at the factors affecting what we eat and plan to face them head-on.
- Appetite: this is influenced by mood, activity level and type, types of foods eaten (and how satiating they are or are not), age, sleep, stress, gender, anxiety, and environment.
- Food Consumed: influenced by culture, religion, traditions, feelings, emotions, access, education, socioeconomic status, preference, and perception of food.
- Food Absorbed: influenced by gut microbiome, gastrointestinal health, amount of stomach acid, medications, anxiety, hormones, and age.
- Mental Factors: influenced by perception of self, control or lack-thereof, stress, anxiety, depression, life events, and emotions.
Weight management can be complicated. The simplistic way of explaining how to lose weight is one must burn more calories than they intake and absorb. Calories burned > calories in = weight loss. It makes sense that “move more, eat less” is a saying. However, each side of this energy (calorie) balancing equation is influenced by several factors- more than just exercise and what we eat. These influences make what seems like a simple equation incredibly complex and dynamic. Good news is Hancock Wellness Center has a clinically trained team that understands the complexity of weight management. All variables are considered by the team to better equip patients and clients with the tools needed to reach goals that last!
Sabrina Goshen, MS, RD, LD
Hancock Wellness Center – Greenfield