The 16-30-5 Eating Rule
Balance protein, raise fiber, and limit added sugar
- Difficulty
- Moderate
- Time to result
- ~ongoing to results
- Steps
- 5
- Confidence
- 99%
Yeo offers three numbers as a simple way to structure a sustainable diet without prescribing one named eating pattern: about 16 percent of daily energy from protein, 30 grams of fiber, and no more than 5 percent of daily energy from added sugars. He defines added sugars as sugars not bound within fiber and includes syrups in that group. The mechanism combines the greater fullness he attributes to protein and fiber with a limit on easily consumed added sugar. He also cautions against simply maximizing protein, saying excess protein can place demands on the kidneys, particularly when it is not being used to support training. These are general targets presented in the episode, not a personalized treatment plan, and the transcript does not establish that they guarantee weight loss for every person.
Origin
Extracted from The Diary of a CEO. Giles Yeo presents the three-number rule near the end of the episode as the practical conclusion of his book Why Calories Don't Count.
Core principles
- 01Use food quality targets instead of relying on calorie totals alone
- 02Keep protein near a moderate share rather than maximizing it
- 03Increase fiber toward a clear daily target
- 04Limit sugars added outside intact food structure
- 05Apply the numbers to a diet that fits the person
How to run it
- 1
Map the Current Pattern
Review an ordinary day of eating and identify the main sources of protein, fiber, and added sugar. Use this as a baseline rather than changing everything at once.
Pro tip Include plant proteins such as beans and tofu as well as animal sources when they suit your diet.
Watch out A rough food review is not a medical or nutritional diagnosis.
- 2
Set Protein Near 16 Percent
Aim for roughly 16 percent of daily energy from protein. Yeo presents this as a moderate target, not an instruction to maximize protein.
Pro tip Use beans, tofu, or other suitable sources; Yeo says the target does not require eating steak.
Watch out The episode says very high protein intake can stress the kidneys; clinical needs require individualized advice.
- 3
Build Toward 30 Grams of Fiber
Increase fiber-containing foods until the daily pattern approaches 30 grams. Yeo contrasts this target with an average UK intake he describes as roughly half that amount.
Pro tip Choose changes that fit meals you already enjoy so the increase remains sustainable.
- 4
Cap Added Sugar at 5 Percent
Keep sugars added to foods or consumed outside intact fiber at 5 percent or less of daily energy. Treat syrups and similar sweeteners as added sugar rather than special exceptions.
Pro tip Start with frequently consumed sweet drinks or foods where the added sugar is easiest to spot.
Watch out The percentage is a general target from the episode, not a guarantee of a particular health outcome.
- 5
Fit the Rule to Real Life
Apply all three targets within an eating pattern you can maintain psychologically and practically. Review whether the pattern is sustainable instead of treating short-term restriction as success.
Pro tip Change the surrounding diet style before abandoning the three targets themselves.
Watch out Do not let numerical targets create food fear or rigid, compulsive eating.
In the wild
Yeo says the three targets can be applied to keto or another preferred diet. A person choosing a lower-carbohydrate pattern would still keep protein moderate, seek fiber-rich foods compatible with that pattern, and limit added sugars rather than treating the diet label as sufficient.
→ The named diet becomes subordinate to three food-quality checks.
Illustrative example: someone reviews a typical week, adds beans and vegetables to raise fiber, replaces a regular sweet drink to reduce added sugar, and adjusts meals so protein stays near the stated target. They make one change at a time and judge whether the pattern remains practical.
→ The person moves toward all three targets without adopting a rigid menu.
Common mistakes
Maximizing Protein
Yeo calls 16 percent a sweet spot and explicitly warns against treating more protein as automatically better.
Counting Syrups as Exempt
The episode includes maple syrup and agave nectar within added sugars rather than treating them as exceptions.
Forcing an Unsustainable Diet
The rule is intended to work across diet styles; using it to justify a pattern that cannot fit ordinary life defeats the episode's sustainability message.
Is it for you?
Best for
It is best for adults seeking a simple structure for a sustainable eating pattern rather than a highly restrictive diet.
Not ideal for
It is not an individualized prescription for anyone whose medical or psychological needs require specialist dietary guidance.
From the transcript
“16 is a sweet spot”
“30 grams we want to aim for”
“keep it to five percent or less”
From the episode
The Weight Loss Scientist: You've Been LIED To About Calories, Dieting & Losing Weight: Giles Yeo