Fit Nutrition library

Nutrition Guides

Clear, practical nutrition guides that turn everyday food questions into simple decisions — how much protein you actually need, what to eat before a workout, how to read a label, and which choices are worth your attention. Every guide is written in plain language and backed by trusted sources, so you can act on it the same day.

137 guides

All guides

Sodium and Potassium: What They Do to Blood PressureWeight Loss

Sodium and Potassium: What They Do to Blood Pressure

Sodium potassium ratio affects water retention and fat loss. Learn how electrolyte balance supports metabolism and reveals genuine weight loss.

6 min read
Soluble vs Insoluble Fiber: What Each One Actually DoesWeight Loss

Soluble vs Insoluble Fiber: What Each One Actually Does

What soluble and insoluble fiber each actually do, which one matches which problem, the one claim soluble fiber alone can make, and where to get both.

5 min read
Anti-Inflammatory Foods: What the Evidence Actually SupportsSpecial Diets

Anti-Inflammatory Foods: What the Evidence Actually Supports

Anti-inflammatory foods without the hype: why no agency defines the diet, which patterns pooled research supports, and where the evidence on fibre and whole grains stops.

7 min read
Protein Shake for Weight Gain: How to Build a Calorie‑Rich, Muscle‑Friendly ShakeProtein

Protein Shake for Weight Gain: How to Build a Calorie‑Rich, Muscle‑Friendly Shake

Protein shake weight gain requires more than just protein powder. Learn how to build high-calorie, muscle-friendly shakes using whole milk, nut butters, and smart ingredients. Find out why.

4 min read
Nutrient Density: What It Officially Means and How to Use ItCalorie Counting

Nutrient Density: What It Officially Means and How to Use It

There is no official nutrient density score. Here is what FDA and the Dietary Guidelines actually define, the 5/20 rule, the real US nutrient shortfalls, and why NRF, ANDI and Nutri-Score are not authoritative.

11 min read
Holiday Eating: What One Plate Actually Costs, and What the Research SaysMindful Eating

Holiday Eating: What One Plate Actually Costs, and What the Research Says

Average holiday weight gain is under a pound, not five. A Thanksgiving plate costed from USDA data, the sodium surprise, and turkey safety rules.

11 min read
Caffeine and Athletic Performance: The Dose, the Timing, the MythsMuscle & Performance

Caffeine and Athletic Performance: The Dose, the Timing, the Myths

The ISSN position stand dose range, what caffeine improves and by how much, why the dehydration myth is retired, and whether you need to cycle off it before competition.

12 min read
Sodium Intake for Athletes: How Much Do You Actually Need?Endurance

Sodium Intake for Athletes: How Much Do You Actually Need?

Sodium athletes need depends on sweat rate and workout duration. Learn how much to consume and when to optimize performance safely.

5 min read
Carbohydrate Loading for Endurance Athletes: Science-Based Timing and Portion StrategiesCarbohydrates

Carbohydrate Loading for Endurance Athletes: Science-Based Timing and Portion Strategies

Carbohydrate loading athletes requires strategic timing and portion control. Learn evidence-based protocols to maximize glycogen stores before endurance events.

9 min read
How to Lose Body Fat: The Numbers With Sources Behind ThemMetabolism & Fat Loss

How to Lose Body Fat: The Numbers With Sources Behind Them

Fat loss is a complex process that involves more than just cutting calories or increasing exercise. At its core, fat loss occurs when the body..

7 min read
A Step-by-Step Guide to Macro CalculationMacronutrients

A Step-by-Step Guide to Macro Calculation

How to set macro targets from your goal, calculate the grams, track them without losing your mind, and adjust when progress stalls.

9 min read
Are Mushrooms Healthy? What the Numbers ShowSuperfoods

Are Mushrooms Healthy? What the Numbers Show

Mushrooms are low in calories and the only produce aisle source of vitamin D. The numbers across eleven varieties, and where they fit in a diet.

4 min read
Eating Well on a Budget: What USDA Says It Actually CostsNutrition Basics

Eating Well on a Budget: What USDA Says It Actually Costs

The official Thrifty Food Plan figures, USDA-named cheapest proteins, the frozen-vs-fresh evidence, and the income-share data behind the feeling that healthy food costs more.

8 min read
The Insulin Index: How Different Foods Trigger Insulin Response and Affect Fat StorageCarbohydrates

The Insulin Index: How Different Foods Trigger Insulin Response and Affect Fat Storage

Insulin index foods affect how much insulin your body releases and fat storage. Learn which foods trigger high responses and practical strategies to moderate them.

11 min read
Everything You Need to Know About ProteinMacronutrients

Everything You Need to Know About Protein

The RDA is 0.8 g/kg; active adults are advised 1.2-2.0 g/kg. The numbers, who each one is for, and why timing matters far less than daily total.

7 min read
How to Increase Your Metabolism: What the Numbers Actually AllowMetabolism & Fat Loss

How to Increase Your Metabolism: What the Numbers Actually Allow

Where daily energy really goes, why lean tissue explains 60-80% of the difference between people, the true calories-per-pound of muscle, and what does not work.

7 min read
Nutrition Recovery Guide for Deload Weeks: Fueling Rest Days and Active RecoveryPre & Post-Workout

Nutrition Recovery Guide for Deload Weeks: Fueling Rest Days and Active Recovery

Nutrition deload weeks support recovery by adjusting carbs and calories while keeping protein steady. Learn how to fuel rest days properly.

7 min read
How to Build a Sustainable Nutrition Habit: Expert Strategies for Long-Term SuccessMindful Eating

How to Build a Sustainable Nutrition Habit: Expert Strategies for Long-Term Success

Learn practical strategies to build sustainable nutrition habits through small changes, habit stacking, and behavior-based approaches that actually stick.

7 min read