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

Food Combining: What Actually Affects DigestionFoods & Nutrients

Food Combining: What Actually Affects Digestion

Food combining digestion works through smart pairings. Learn which foods enhance nutrient absorption and support digestive health effectively.

5 min read
How Accurate Are Calorie Labels? The Legal MarginsCalorie Counting

How Accurate Are Calorie Labels? The Legal Margins

Nutrition labels are allowed to round, and serving sizes are not recommendations. How far the numbers can legally be off, and what to do about it.

6 min read
Pedometer to Calorie Converter: How to Translate Daily Steps into Energy BurnedCalorie Counting

Pedometer to Calorie Converter: How to Translate Daily Steps into Energy Burned

Learn how a pedometer steps to calories converter estimates energy burned from daily steps, helping you track activity for weight management. Learn more.

5 min read
Sports Drinks vs Energy Drinks: What’s the Difference?Endurance

Sports Drinks vs Energy Drinks: What’s the Difference?

What is actually in each, who each one is for, the risks attached to both, and how to tell which - if either - belongs in your bag.

10 min read
Food Sensitivity vs Food Allergy: How to Identify and Manage Your TriggersSpecial Diets

Food Sensitivity vs Food Allergy: How to Identify and Manage Your Triggers

Food sensitivity vs allergy explained: learn how timing, symptoms, and testing differ. Discover practical ways to identify your triggers.

8 min read
Inflammation and Diet: What the Science Actually MeasuresSpecial Diets

Inflammation and Diet: What the Science Actually Measures

What CRP and hs-CRP measure, why no agency recommends testing healthy people, what the Dietary Inflammatory Index really is, and why studies on inflammation and diet disagree.

8 min read
Iron Rich Foods: The List, and What Your Body AbsorbsFoods & Nutrients

Iron Rich Foods: The List, and What Your Body Absorbs

The food list is the easy part; absorption is the whole story. Heme vs non-heme iron, what raises and lowers absorption, and the 1.8x vegetarian multiplier.

5 min read
Mindful Eating Apps: What They Do and How to Choose OneMindful Eating

Mindful Eating Apps: What They Do and How to Choose One

What mindful eating apps actually do, the features worth having, and how to pick one for beginners or for tracking progress.

9 min read
High‑Fiber Foods List: 25 Everyday Options to Boost Digestion and SatietyFoods & Nutrients

High‑Fiber Foods List: 25 Everyday Options to Boost Digestion and Satiety

High fiber foods support digestive health and satiety. Learn about 25 nutrient-dense options and how to add them to your diet gradually. Discover how.

7 min read
Seed and Nut Nutrition Compared: Numbers and LimitsFoods & Nutrients

Seed and Nut Nutrition Compared: Numbers and Limits

Seeds nuts nutrition comparison shows how almonds, walnuts, chia, and hemp differ. Choose based on your fiber, protein, or omega-3 needs. Learn more.

8 min read
How Accurate Are Calorie Tracking Apps? What to TrustMeal Planning

How Accurate Are Calorie Tracking Apps? What to Trust

Calorie apps stack four estimates: the database entry, the rounded label, a predicted target and exercise burn. Where each goes wrong, and how to track anyway.

6 min read
Seasonal Produce Guide: What’s Actually in Season, and How to Keep ItFoods & Nutrients

Seasonal Produce Guide: What’s Actually in Season, and How to Keep It

USDA's seasonal produce lists for spring, summer, fall and winter, plus choosing and storing advice, FDA washing rules, and what "certified" at a farmers market means.

7 min read
Phytonutrients: What They Are and What They DoVitamins & Supplements

Phytonutrients: What They Are and What They Do

Phytonutrients are plant compounds, not nutrients in the formal sense. What the research supports, what keeps failing in trials, and where to get them.

5 min read
Supplement Forms: Does It Matter Which Kind You Buy?Foods & Nutrients

Supplement Forms: Does It Matter Which Kind You Buy?

Does the form of a supplement change absorption? What NIH says about B12, calcium, magnesium, folate, zinc, vitamin D and E forms — and where the marketing has it backwards.

10 min read
Nutrient Cycling for Fat Loss While Preserving Muscle Mass: A Science-Backed ApproachMuscle & Performance

Nutrient Cycling for Fat Loss While Preserving Muscle Mass: A Science-Backed Approach

Nutrient cycling fat loss strategies help preserve muscle while losing weight. Learn science-backed macro cycling and calorie day timing. Discover how.

9 min read
Water or Electrolytes? Hydration by Exercise TypePre & Post-Workout

Water or Electrolytes? Hydration by Exercise Type

When you actually need electrolytes instead of water, how to measure your own sweat rate, and why drinking too much is the more dangerous mistake. Figures from the ACSM position stand.

8 min read
Diet for Visible Abs: What Actually Determines the ResultWeight Loss

Diet for Visible Abs: What Actually Determines the Result

Why the "ab diet" is the wrong frame, which part of fat loss has an actual number behind it, where protein fits, and the product claims to walk away from.

6 min read
Recovery Nutrition Window: Myth vs Reality for Post-Workout EatingPre & Post-Workout

Recovery Nutrition Window: Myth vs Reality for Post-Workout Eating

Recovery nutrition window myth: what science actually says about post-workout meal timing, anabolic windows, and what really drives results.

6 min read