Body Composition & Nutrition
Laying the Foundation:
Welcome to the third annual Booty by Bret competition! This year we're wanting to provide information to guide you through the journey and provide background information as to what goes into improving your physique. Understanding the fundamentals of fitness is essential to set realistic goals, create an actionable plan to achieve it, and to be confident in your ability to make informed decisions along the way
Understanding Body Composition:
1.1 What Influences Body Composition?
Body composition is the proportion of body fat and fat-free mass. When we talk about “improving” body composition, we’re typically referring to increasing fat-free mass (via skeletal muscle), decreasing body fat, or a combination of the two.
Body fat is the body’s primary energy storage tissue, which is primarily dictated through energy balance. Regardless of food source, when you consume more energy (calories or kilojoules) than your body utilizes (calorie surplus), you will store the excess as body fat. Alternatively, if you consume less calories than your body utilizes, your body will make up the difference by burning stored fat. Lastly, if at equilibrium, your fat balance will stay the same (often called “maintenance”). You can view the fat balance as a math equation:
Energy in – energy out = energy balance
While there are a multitude of other factors which influence both the energy out and energy in aspect of the equation, the equation will still reign true (i.e., if hormonal abnormalities result in decreased energy output, the energy balance will still apply).
Muscle mass is primarily a function of nitrogen (protein) balance, NOT energy balance. The same general principles of energy balance apply to nitrogen balance as well, where the goal of gaining muscle mass will necessitate being in a nitrogen surplus. More specifically, the equation will be:
Muscle protein breakdown – muscle protein synthesis = muscle balance
Despite energy balance influencing nitrogen balance, they are not 1:1 correlated, making it possible for you to be in a nitrogen surplus and energy deficit, which is the foundation of recomping. Energy balance’s influence on nitrogen balance will make it more difficult to improve body composition from both sides, and will generally decrease the more advanced you are.
Physical activity will also influence the nitrogen balance equation. Lifting weights will stimulate muscle protein synthesis at a greater rate than muscle protein breakdown. However, muscle protein synthesis being stimulated isn’t enough in isolation, as it needs amino acids to actually synthesize new muscle protein.
1.2 How Body Composition Changes Over Time
Week 2 will lay out specifics of goal setting and general planning, but before being able to do so, it’s important to understand the rate of change you can reasonably achieve.
Have you ever wondered where the idea that “1lb = 3,500 Calories” comes from? Let's break it down: While it may be counterintuitive, adipose tissue contains more than just body fat, rather, it’s a combination of primarily stored triglycerides (fat), fluid, and protein. As we’ll go over in the Basics of Nutrition section, 1 gram of fat has 9.0 Calories. Since there are 453.6 grams per pound, and each pound of adipose tissue is around 85% fat by weight, we get the ~3,500 Calories per pound of fat from:
9 Calories / Gram * 453.6 Grams / Pound *.85 ≈ 3,500 Calories per Pound
Interestingly, if you’re to just calculate the total amount of pure fat being lost, 1lb of fat is 4,086 Calories.
In most cases, the recommended rate of fat loss is between 0.5-3 pounds per week, depending on your starting point, genetics, and goals. In ideal conditions, fat loss tends to have a fairly linear relationship over time. In practice, fat loss often gets falsely equated for weight loss, which can lead to frustration and confusion. Fear not, this is often to be expected, and frequently doesn’t require any intervention.
The rate of change for muscle is a lot trickier to predict. While fat loss is subject to genetics, muscle gain tends to be much more influenced by genetics. Individual genetics aside, muscle tends to grow at a decreasing rate, so you can expect to see the most growth within the first 2 years of your training, then it will taper down. Interestingly, there’s no definitive data plotting quantitative measures, however, a general estimate for women is as follows:
Basics of Nutrition:
2.1 Calories: The Building Blocks of Nutrition
Now that we’ve established the importance of energy balance, let’s give into where the “energy in” actually comes from. We get our energy from macronutrients found in food and drinks. The 3 primary energy-yielding macronutrients are carbohydrates, proteins, and fats. A caveat to this is alcohol, which technically is not a macronutrient, but it yields energy.
Carbohydrates: 4 Calories / gram
Protein: 4 Calories / gram
Fats: 9 Calories / gram
Alcohol: 7 Calories / gram
These represent average energy-yield, as subsets of these nutrients contain different energy yields (for example, soluble fiber, a carbohydrate, contains around 2 Calories per gram. This isn’t to say you should concern yourself with specifics of the exact Calories beyond what food labels tell you, however, this can shine light on some dietary strategies which we’ll cover in a few weeks.
2.2 Macronutrient Ratios for Muscle Gain and Fat Loss
Macronutrients serve different biological functions. Protein acts as a building block for tissues and cellular repair; carbohydrates provide your body with an efficient energy source, and fats help hormone production and absorption.
Determining how to split up your macros will depend on your goals, your method of monitoring your food intake, your lifestyle, and your dietary habits & preference. The two fundamental factors which will need to remain constant are a fairly narrow daily Calorie goal, and a protein goal. In a normal mixed diet, carbohydrates and fats can be used interchangeably when you equate their energy (remember that carbohydrates have 4 Calories per gram and fat has 9 Calories per gram, so you’ll be able to consume more grams of carbohydrates for the same calorie amount) without it influencing fat loss and/or muscle gain. If you’re someone who enjoys a bit more flexibility in your day-to-day diet, setting a Calorie goal, a protein goal, and filling the rest of your diet with any combination of fats and carbohydrates will suffice. However, not everyone will have the same dietary preference, and some may find it easier to have set macronutrients (which as long as you’re not consuming alcohol on top of it, will necessarily hit your Calorie target).
To optimize muscle growth, the research shows around 0.8-1.0 grams per pound of total bodyweight to be sufficient, eating anything more than that isn’t detrimental, but won’t contribute to hypertrophy any further. To determine your Calorie & protein, or macronutrient needs, please see the Tools for Success section below.
Calorie calculators work by looking at average datasets and using an activity multiplier based on your perceived activity levels. Although this may seem trivial, it’s important to note that as with any Calorie calculator, it offers a good general starting place without taking your individual lifestyle, activity levels, and body composition into account. This isn’t to say they don’t work, but you should take your body’s trends to make adjustments to get a more precise Calorie target for your goals.
2.3 Dieting for Health vs. Fat Loss
While energy balance ultimately dictates changes in fat balance and macronutrients can influence body composition, there's much more to nutrition than just Calories and macronutrients. The quality of your diet plays a significant role in overall health, longevity, how you feel day to day, and how sustainable your diet is. For instance, it's entirely possible to lose weight on an unhealthy diet if you're in a calorie deficit, just as you could gain weight eating a highly nutritious diet if you're in a surplus.
This highlights a key truth: energy balance is the primary driver of fat loss, no matter the dietary approach you choose. Whether you're following low-carb, low-fat, keto, carnivore, or any other plan, the same principle applies - fat loss occurs when you're in a calorie deficit. However, the long-term sustainability and health outcomes of your diet depend on more than just energy balance. That's where the importance of food quality, micronutrients, and overall dietary patterns comes into play. While we encourage you to eat a healthy, well-rounded diet, there are several considerations that go into eating healthy, and an infinite number of ways to set up a healthy diet that can promote your body composition goals, so that’s outside the scope of what this can reasonably accomplish.
2.4 Methods for Diet Tracking
Moving past the science, how do you put this into practice? Given the quantitative nature of tracking calories and macronutrients, it’s important to find methods and develop methods that align with your experience, preferences, and goals. Although the more accurate you are with nutrition tracking, the more linear your progress tends to be, tracking can feel overwhelming and inconvenient. Manually weighing and tracking isn’t mandatory for long-term progress (and in most cases, isn’t sustainable), but developing a healthy relationship with food proportions will be an important skill. Ideally, intuitive eating, where you’re making conscious food decisions but not letting it hinder your lifestyle is the goal. Below is a step-by-step guide to help you build your tracking skills over time:
Step 1: Develop Awareness
- Start looking at nutrition labels, paying attention to the Calories, Total Carbohydrate, Total Fat, and Protein sections, along with the portion size.
- Use visual guides to get a sense of proportions.
- Aim to consume foods which have low energy density (large serving sizes with fewer Calories) and minimize foods with high calorie density.
Step 2: Establish Your Baseline
- Use a digital food scale to weigh out proportions.
- Initially, aim to eat what you normally would to get an idea of how many servings you have (this can help to establish foods which you may have a tendency to overconsume Calories).
Step 3: Log Your Intake
- Begin logging your meals and snacks using a tracking app or paper and pen while continuing to weigh your food.
- Pay attention to what a serving size looks like for various foods to help develop portion size awareness.
Step 4: Full Tracking
- Log and aim to hit your target Calories and protein, or macronutrients. Give yourself time during this time period, as accurately tracking takes time.
- Be patient with yourself - accurate tracking takes practice and consistency to refine.
Step 5: Transition to Estimation
- As you become more comfortable with logging and portion sizes, challenge yourself to estimate food quantities without weighing them.
- Use the food scale occasionally to check your estimations and reinforce accuracy.
Step 6: Intuitive Eating
- Aim to make conscious dietary choices without overthinking the nutritional values.
- Adjust portion sizes in response to your biometric trends in relation to your goal.
3. Tools for Success
3.1 Calorie and Macro Calculators
Macros and Calories Calculator
Select a Calculator
Calories and Protein Calculator
Recommended Calories and Protein:
Macronutrient Calculator
Recommended Macronutrients:
4. Actionable Takeaways
4.1: Key Takeaways
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Energy Balance Determines Fat Changes:
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Whether you’re gaining, maintaining, or losing body fat depends entirely on your energy balance.
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Calorie Surplus: Leads to fat gain.
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Calorie Balance (Maintenance): Yields no change in fat.
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Calorie Deficit: Results in fat loss.
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Nitrogen Balance Drives Muscle Changes:
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Your muscle gain, maintenance, or loss is dictated by nitrogen (protein) balance
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While energy balance influences this, it doesn’t completely determine potential for muscle growth changes
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Recomping is Possible: You can gain muscle and lose fat simultaneously under the right conditions.
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Fat Loss ≠ Weight Loss:
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Weight loss is influenced by hydration status, glycogen retention, etc.
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These often get confused, leading to frustration when the scale doesn’t reflect fat loss
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Consistency and Patience are Key:
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Sustainable progress requires time, effort, and consistency.
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Focus on long-term trends rather than daily fluctuations.
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Healthy Eating Goes Beyond Calories:
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While energy balance is essential for fat balance, the quality of your diet plays a vital role in health, performance, and sustainability.
4.2: Steps to Take
If You’re Not Familiar with Tracking:
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Start by going through the Steps to Develop Awareness outlined above.
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Begin looking at nutrition labels, paying attention to calories, macros, and portion sizes.
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Use visual portion guides to better understand food proportions.
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Gradually progress through the steps to build dietary awareness and tracking skills.
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Focus on improving your dietary habits one step at a time to set the foundation for long-term success.
If You’re Familiar with Tracking:
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Calculate Your Macros:
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Use the macro calculator to set your daily protein and calories, or macro targets based on your Calories and personal goals
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Start Tracking:
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Log your meals and snacks using your preferred tracking method (app or paper and pen).
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Focus on consistently hitting your calorie and protein or macro targets to optimize progress.