Nutrition Pt IV: Body Composition

A More Realistic Look at Body Composition and Nutrition

People often start “diets” to improve body composition—usually to lose weight. While health is part of the motivation, the primary driver tends to be physical appearance. The problem? Most people treat dieting as a temporary event, not a lasting lifestyle change. When you say, “I’m going on a diet,” you’re also saying, “I plan to stop this at some point.” This mindset is what fuels the all-too-common cycle of yo-yo dieting.

The Trend of Gradual Weight Gain

If you follow the Standard American Diet (SAD), chances are you're slowly gaining weight. Most people put on 2–5 kg (5–10 lbs) annually. This is especially true around the holidays, when food is more abundant and physical activity tends to drop. Over time, this steady gain adds up—and people wonder how they ended up overweight

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What Does It Mean to “Go on a Diet”?

Technically, everyone is on a diet—it’s just the sum of what you eat. When people say they’re “starting a diet,” they usually mean they’re attempting calorie restriction in some form. Common approaches include:

• Outsourcing food choices (e.g., SlimFast, Jenny Craig)

• Tracking calories using apps like MyFitnessPal or Cronometer

• Time-restricted eating (like intermittent fasting)

• Cutting out specific macronutrients (e.g., carbs or fats)

At the core of most diets is the idea of eating fewer calories than you burn—a principle known as being hypocaloric.

Peter Attia’s Calorie Restriction Framework

Dr. Peter Attia categorizes calorie restriction into three main types:

1. Absolute Caloric Restriction – Simply eating less.

2. Macronutrient Restriction – Cutting carbs, fats, or both.

3. Time-Restricted Feeding – Limiting when you eat (e.g., eating only between 12–8 PM).

Let’s break those down further:

1. Absolute Caloric Restriction

This is the most straightforward: eat less food overall. Since fat contains 9 kcal/gram and carbs/protein contain 4 kcal/gram, reducing portion sizes—especially of calorie-dense foods—can lead to weight loss.

Tools people use:

• Calorie-tracking apps

• The 5:2 diet (skip meals 2 days/week to reduce weekly calories)

• Meal prep or meal replacement plans

Caution: While tracking can help, it sometimes fosters guilt or disordered eating. If it creates more stress than benefit, it may not be worth it.

2. Time-Restricted Feeding (TRF)

TRF involves eating within a set window each day—commonly 16:8 (fast for 16 hours, eat within 8). A typical window might be noon to 8 PM, which fits with many people's natural tendencies.

Key benefits:

• Simplifies eating

• Reduces nighttime snacking

• May improve sleep or acid reflux symptoms if eating stops before bedtime

But remember: Weight loss from TRF still comes down to fewer total calories.

3. Macronutrient Restriction

This includes:

• Low-fat diets (popular in the 90s)

• Low-carb or “keto” diets (popular today)

• High-protein focus (based on the “protein leverage” theory)

The keto diet, in its clinical form, involves <50g carbs/day and measurable ketone levels—rarely achieved by casual dieters.

The protein-first approach suggests aiming for ~1g protein per pound of body weight. Eating protein-rich meals early in the day can decrease nighttime cravings.

Counterpoint: Groups like the American College of Lifestyle Medicine argue against high animal-protein diets, citing potential links to chronic disease.

Energy Expenditure: Why Activity Still Matters

Your total calorie burn includes:

• Basal Metabolic Rate (BMR): The energy to stay alive

• Thermic Effect of Food (TEF): Calories used to digest food

• Non-Exercise Activity Thermogenesis (NEAT): Fidgeting, walking, chores

• Exercise: The most variable factor

Fidgety people with high NEAT (like me) burn more calories daily. But athletes or people with intense training needs may require thousands of calories just to maintain their weight.

What About Food Sensitivities?

Some argue that low-level food sensitivities cause inflammation and impact body composition. Common triggers include:

• Wheat

• Dairy

• Eggs

• Soy

• Legumes

• Nuts

While the science is mixed and many lab tests are unreliable, anecdotal evidence (including from my own practice) suggests that elimination diets can be helpful for select individuals.

Personal Reflections: What’s Worked for Me

I’ve experimented with a lot. Here are a few notes from my own journey:

• Best body composition: Came from Mario DiPasquale’s Anabolic Solution (very low carb during the week, carb refeed on weekends).

• Leanest I’ve been: During deployment—running, lifting, BJJ, lower cumulative stress, high activity (25k steps/day), no alcohol. This was also the easiest things were nutritionally as all my meals were prepared and I just selected meat and veggies for every meal.

• Biggest weight gain: First year of med school—sitting all day, lifting heavy and competing in powerlifting, eating lots of Papa John’s. (Effective for bulking… not health.)

• Effective weight loss: More running, Brazilian jiu-jitsu, and salads for dinner. Dropped down 25lb within 6 months.

• Now? I’m on the “ensure I eat” diet. Stress suppresses appetite. I use exercise as an outlet and have to intentionally eat high-calorie meals to maintain weight and avoid injury. I prefer steak to sweets, which helps me naturally avoid excess carbs when inactive. If weight starts to go up, I tend to modify activity more than I do diet. I'll just increase running which tends to drop body weight.

Final Thoughts

There’s no one-size-fits-all approach to diet or body composition. What matters is sustainability, self-awareness, and matching your food choices to your goals, values, and lifestyle.

Key Takeaway: Instead of “going on a diet,” think about how to eat in a way that supports the life or goal that you want—now and in the future.