The three components of energy expenditure in which our bodies burn calories: Basal Metabolic rate, Thermic Effect of Food, Non-Exercise Adaptive Thermogenesis (NEAT), and Activity Energy Expenditure.
THE THREE COMPONENTS METABOLISM FOR FAT LOSS SUMMARY
- Cardio vs. Diet for Fat Loss: While diet alone can lead to a decrease in metabolism, with a loss of both fat and muscle, exercise, especially resistance exercise, is more effective at preserving muscle. A study found that a group that reduced calorie intake lost more muscle mass compared to a group that increased exercise to burn the same amount of calories.
- Understanding Energy Balance: Energy balance is governed by the laws of thermodynamics. Weight gain or loss is determined by the balance between caloric intake and expenditure. The article cites an example of a teacher who lost 60 pounds by eating at McDonald’s daily but maintained a caloric deficit.
- Components of Energy Expenditure: The three main components that determine how our bodies burn calories are Basal Metabolic Rate (BMR), Thermic Effect of Food (TEF), and Activity Energy Expenditure (which includes both exercise and non-exercise activities). BMR accounts for the majority of daily calorie burn, representing the energy needed for basic life functions.
- NEAT’s Impact on Obesity: Non-Exercise Activity Thermogenesis (NEAT) refers to the energy expended through non-conscious activities like fidgeting. NEAT can vary significantly among individuals and plays a crucial role in weight management. Obese individuals tend to have lower NEAT levels than their lean counterparts, which contributes to their weight challenges.
9/28 CARDIO VS DIET FOR FAT LOSS: WHICH IS BETTER?
When trying to lose body fat, most people perform a combination of exercise and calorie restriction. The research is conclusive that diet alone will cause the loss of both fat and muscle, whereas exercise is much better at preserving muscle, especially resistance exercise.
Few studies have compared a direct comparison of a daily reduction in calories from diet alone to increasing exercise daily to burn more calories. In general, it’s much easier to create a caloric deficit by diet compared to increasing the number of calories burned by exercise. For example, cutting calories by 500 is easier than doing cardio to burn 500 calories, as this is more fatiguing. Researchers took overweight males and compared two forms of weight loss.
One group cut calories by 700 calories per day but did not exercise. The diet comprised 55-60% carbohydrates, 15-20% protein, and 20-25% fat. The other group maintained their normal caloric balance but exercised to burn 700 calories daily for 12 weeks. The caloric deficit was created entirely by increasing energy expenditure thru exercise.
The average time spent on the treadmill was 60 minutes per day at an exercise intensity just below 80% of the maximum heart rate. At the end of the study, both groups lost an identical amount of weight, roughly 17 pounds for the diet-only group and 16 pounds for the exercise-only group (i.e., 8% of their total weight), but the composition of the weight loss was dramatically different.
The cardio-only group lost -4.3% of body fat, while the diet-only group lost -3.4%. The cardio-only group lost less muscle mass (-2.2 pounds) compared to the diet-only group (-4.8 pounds). A direct comparison is more revealing as the diet-only group lost 70% of their body fat from fat and 30% from muscle. Conversely, the cardio-only group lost 85% of their weight from fat and only 15% from muscle.
The diet-only group also had a bigger drop in their resting energy expenditure because they lost more muscle. The diet-only group resting energy expenditure dropped by -211 calories, while the cardio-only group had a drop in resting energy expenditure by -126 calories. This means the diet-only group had a 40% greater drop in resting energy expenditure than the cardio-only group.(45)
The study suggests that although it is easier to create a deficit by diet, adding exercise is a better way to burn fat and preserve muscle. It makes sense to cut back on calories and increase energy expenditure thru exercise to create a deficit. However, as the study proves, it is possible to increase fat loss thru exercise alone. What would have been more appealing if they made a direct comparison with resistance exercise, which would have resulted in less lean muscle mass loss? It should be mentioned that cardio is just a tool for fat loss; you can either do more and eat less or a combination of both, which is much easier. You can skip cardio, do resistance exercises, and cut back on calories.
UNDERSTANDING ENERGY BALANCE
Energy balance is based on laws of thermodynamics, whereby energy cannot be created or destroyed; it can only be transformed from one form to another (i.e., gain or lose weight). Gaining or losing weight is a function of “tipping the balance” on the energy balance scale, favoring caloric excess or caloric deficit.
The reason the teacher who ate at McDonald’s every day for 90 days and still lost 60 pounds is a function of being in an energy deficit. (1) He ate two Egg White Delights, a bowl of oatmeal, and 1 percent milk for breakfast. He alternated between a Southwest Salad or Bacon Ranch Salad for lunch with fruit parfait and apple slices. For dinner, he ate a value meal. He ate a small serving of fries just about every day. He calculated his daily caloric needs and ate below his daily energy expenditure. This is not magic; he just ate in a caloric deficit. He probably lost a ton of muscle, but it’s proof of the concept that you must be in a caloric deficit to lose weight.
Humans are well-equipped to store fat. The human body has a remarkable capacity to sense a caloric deficit. Your body has no desire to get lean or lose body fat. Our bodies are better equipped to replace lost weight and rapidly sense a caloric deficit. Energy compensation is more likely when you reduce rather than increase energy consumption.
THE THREE COMPONENTS METABOLISM FOR FAT LOSS
For example, the classic study on energy compensation lasted 14 days; subjects were blind to the number of calories they consumed. The great thing about this study was it was carried out in a metabolic laboratory, so the researchers knew exactly how many calories they were consuming. The researchers secretly replaced their food with lower-calorie, lower-fat foods. For example, the low-calorie replacement replaced their regular soda of 192 calories with a Diet Cola with 4 calories. The subjects could eat as much as they wanted. Despite the caloric replacement of lower-calorie foods, which resulted in a 500 caloric deficit; however, the subjects ate more of their regular food and overcompensated for the reduced-calorie foods.
Thus, the subjects completely compensated for the calorie loss and upregulated calories accordingly to maintain body weight. (2) Similarly, Drenowatz (2015) acknowledged that humans are better equipped to replace lost weight than avoid weight gain, although the phenomenon is characterized by individual variability.(3) Thus, replacing regular foods with fat-free foods may not be the answer to long-term weight loss. Despite the development of fat-free, low-fat, and “lite” foods, obesity has increased.
There are three major components of energy intake: protein, carbohydrates, fat, and alcohol.
Protein 4 calories
Carbohydrates 4 calories
Fats 9 calories
Alcohol 7 calories
A negative energy balance (i.e., fewer calories consumed) must be established via a smaller energy intake or increased energy expenditure for weight loss to occur. Your body likes to maintain weight, so a complex signaling pathway will drive you to consume more calories. For example, decreasing calories will reduce metabolic rate (i.e., lowering calories burned at rest) and reduce physical activity. (4)
The diverse arrange of physiological consequences that can occur during weight loss depends on: a.) the severity of the caloric restriction .b) the duration of the energy restriction, c.) body composition at baseline, d.) the social environment in which the diet occurs. (5) It was found that eating in the presence of a friend increased caloric intake by 44%, and eating with six others increased caloric intake by 77%.(6)
THE THREE COMPONENTS METABOLISM FOR FAT LOSS
An increase in energy expenditure (i.e., increased exercise or physical activity) will increase appetite signaling hormones, driving you to eat more calories. (7) The appetite response to exercise is highly variable, with some people over-compensating while others were under-compensating. The biological response that drives appetite during caloric restriction is complex. It has been found that for every 2.2 pounds lost, there is an increase in caloric intake by 100 calories. (8)
A J-shaped curve was observed in a meta-analysis of 28 studies comparing the relationship between energy intake and physical activity levels. Cross-sectional studies of low, medium, high, and very high physical activity levels found that the most active individuals consumed the highest amount of calories. (9) The body is trying to maintain homeostasis or its current biological set point in response to dynamic fluctuations in energy expenditure.