The 80/20 Rule for Diet and Health

Chapter summary

Identify the one or two lifestyle changes that make the most difference (the 20%). Do not try to be “good” at everything else (the 80%).
Take something out, rather than adding something to your health program.
If you do not smoke and are not an alcoholic, stop consuming added sugar. Do those first two first.
When sugar is under control, add the next most valuable change: intermittent fasting. Otherwise it will all be too hard.

Joseph Juran, a business-management consultant, named it the Pareto principle after Vilfredo Pareto, who noted in 1906 that 80% of Italy’s land was owned by 20% of the people.
Pareto saw the same pattern in his garden: 20% of the pea pods held 80% of the peas.
In business, 80% of sales often come from 20% of clients. Mathematically it follows a power-law (Pareto) distribution, and many natural systems fit it.

The author says almost certainly, though no one has studied it closely.
The Standard American Diet takes about 15% of calories from added sugar. Many people who remove sugar get 80% of the weight loss they want.
Many people find that cutting one food gives most of the benefit.
Compliance rises when people focus on removing sugar or follow a simple plan such as 5:2.

Traditional view: Obesity is gluttony and sloth, so eat less and move more. That requires self-control, discipline, motivation and long-term commitment.
The author’s view: Most people lack full self-control. Complicated diets are too hard and have too many temptations. Dieting tends to increase weight in the long term. Focus on the few changes that matter most.
Critics of the shortcut: Some say that focusing on a single food ignores balanced nutrition. The author says the rule is a starting point, not the whole program.

List your current habits. Find the one or two that cause most of the harm.
Start with added sugar.
Next, add intermittent fasting (5:2).
Leave vitamins, organic food and other low-value changes for later or skip them.