Nutrition and health, by the evidence

How much protein, fiber or sleep do you actually need?

Plain-language reviews of what published research and clinical guidelines say about protein, fiber, calories, sugar, sleep and water, with the number up front and the body that publishes it named. Every health page carries a named medical reviewer. Educational only, not medical advice.

A balanced meal of salmon, eggs, lentils, and leafy greens on a light table
Daily protein targetA quick estimate from your weight and activity, using commonly cited guideline ranges.
kg
Estimated daily target~84 g/dayA population guideline range, not a personal prescription.
See where these numbers come fromEducational estimate, not medical advice.

This is not medical advice. NourishMark publishes educational reviews of published research and clinical guidelines. It does not diagnose, treat, or replace your own clinician. Dr. Khan reviews NourishMark's health content for medical accuracy. He is not a registered dietitian, he does not hold a United States practising licence, and he is not your doctor. His review does not make anything here medical advice.How we research, write and review

Start here

The questions readers open first

Browse all 66 →
Freshly revised

Recently updated reviews

Browse all →
A person cooking rice in a large pot with steam rising, next to two baking sheets of roasted chicken and vegetables and a row of empty meal-prep containers on a kitchen counter
Food reference

7-Day High Protein Meal Plan (Sample Menu)

This meal plan lays out 7 days of high protein breakfasts, lunches, dinners and snacks, with sample macros, vegetarian swaps, and a weekly grocery list.

25 min read
A man in athletic clothing on a dirt trail, pausing to drink water from a bottle after exerciseEvidence review

High Protein Diet for Muscle Gain: How It Works

This evidence review explains how a high protein diet supports muscle gain, with a protein target range, sample meals,...

25 min read
Overhead bowls of protein, carbohydrate, and fat foods on a light blue table: grilled chicken, lentils, yogurt, cubed tofu, chickpeas, avocado, sweet potato, and whole wheat breadEvidence review

High Protein Diet for Weight Loss: How It Works

This evidence review explains how a high protein diet supports weight loss, with sample meals, macros by calorie...

25 min read
An overhead spread of protein-rich whole foods on a light table: eggs, chicken, salmon, yogurt, beans, lentils, tofu, and nutsEvidence review

High Protein Foods List: Eggs, Chicken, Beans and More

This evidence review lists high protein foods with commonly cited figures, from 2 eggs and 100g of chicken to yogurt,...

32 min read
A dark twin-bell alarm clock on a wood nightstand in a dim bedroom, hands positioned near ten and two, with a bed visible behind itEvidence review

Intermittent Fasting Explained: Schedules and the Evidence

Intermittent fasting explained: the 16:8, 5:2, and alternate-day schedules, what research shows on weight loss versus...

26 min read
An overhead spread of water-rich whole foods on a light table: watermelon, cucumber slices, orange slices, a chilled soup, and a mug of teaEvidence review

Calories in Common Foods: A Quick Reference

This evidence review lists commonly cited calories in common foods, from a banana near 105 and an egg near 72 across...

33 min read
A glass of water being filled from a carafe on a bright kitchen counterEvidence review

How Much Water Should You Drink a Day? The 8 Glasses Myth

This evidence review answers how much water you should drink a day: where 8 glasses came from, what reference intakes...

27 min read
Two people seated across a wooden table, one in a white coat writing in a spiral notebook and one in a beige sweater listening, with a bowl of bananas, an orange and apples on the table and a potted plant against a green wall behind themEvidence review

Vitamin D Deficiency Symptoms: What They Can Mean

Vitamin D deficiency symptoms are commonly linked to fatigue, bone and muscle aches, and mood changes, though none...

26 min read
Two fresh skinless chicken breasts on a light wooden cutting board in a bright clean kitchenEvidence review

How Many Calories in Chicken Breast? (By Size)

Calories in chicken breast run near 140 per 3 oz and 165 per 100g cooked (USDA), scaled by portion size, skinless vs...

32 min read
Quick reference

Commonly cited daily numbers

Guideline figures as published bodies state them, each linking to the full review and its sources. These are population guidelines, not personal targets, and not medical advice.

Who writes this

Thorough, and evidence-based

Editorial process →

Two named people stand behind every review, and the limits of what they can tell you are stated as plainly as their credentials.

How we researchEvery review explains what the published guidance says and attributes it to the body that publishes it, so you can check the current figure yourself. This is evidence-based general information, written to be educational, not medical advice, and never a substitute for your own clinician.
How we make moneyAt the time of writing this site carries no affiliate links and no advertising. No link earns a commission and no company pays for coverage. If that ever changes, the disclosure page will say so first and any paid link will be marked where it appears.
Free to reuseOur protein tool can be embedded on any site, free, with attribution.
By email

Get the meal-plan and nutrition guide by email

Plain-language, evidence-based nutrition, plus a simple meal-plan idea to make eating well a little easier. Tell us your goal and we will email it to you.

Educational only, not medical advice. We store your details to reply to you. See our privacy policy.
For publishers and clinics

Take the protein tool with you

The daily protein target tool is free to embed on your own site. Copy the snippet, keep the attribution link, done.

Put this free bmi and daily calorie tool on your site

Free to use with attribution. Paste this where you want the tool to appear:

Publishers: embed this calculator free