Jason Fung - Processed Vs. Natural Foods (Shocking) | Jason Fung

Short Summary

Main recommendation: Eat natural, whole foods rather than ultra-processed foods, which Jason Fung argues drive overeating and may be contributing to rising obesity, especially among youth. Ultra-processed foods are industrial formulations of cheap energy sources and nutrients plus additives, made through a series of processes that strip out fiber, protein, and natural fats. Fung also suggests that if you don't have time to eat well, you can skip a meal rather than default to a processed option.

Key Points

• Ultra-processed foods are industrial formulations of cheap carbohydrates, fats, and proteins plus additives, and they tend to be the lowest-quality and easiest-to-manufacture ingredients.
• Processing removes fat, fiber, and protein from natural foods, leaving pure carbohydrate that the body does not recognize as food, which makes overeating easy.
• Fung links the 1977 US low-fat dietary guidelines to the government encouraging companies to make low-fat processed foods, which Fung says tasted worse, prompting companies to design products to fill that gap.
• Ultra-processed foods won over the market because they are cheap, shelf-stable, convenient, and highly profitable for manufacturers.
• In a metabolic lab study of 20 adults, those given ultra-processed meals matched for calories, sugar, salt, and fiber ate about 500 more calories per day and gained roughly 2 pounds over two weeks, while those on natural food lost about 2 pounds.

Details Worth Noting

• Concrete instructions: Fung's only explicit action is to avoid defaulting to processed food when busy; if you lack time to prepare natural food, consider skipping that meal, and fasting can help reduce the number of meals you need while keeping you on natural foods you can prepare when needed. Fung notes that popular diets like paleo, ketogenic, or whole-food plant-based all emphasize foods close to nature, and cautions that a plant-based diet of chocolates and pizza isn't healthy just because it removes animal products.
• A 2009 study cited by Fung found the average diet was about 58% ultra-processed foods.
• Data on US youth over about 20 years show ultra-processed foods rose steadily, reaching roughly 65 to 70% of calories by 2017–2018 among older youth, including children ages 2 to 5.
• Ready-to-heat mixed dishes such as pizza and microwave dinners were the biggest growth category, along with sweet snacks and bakery products from 1999 to 2017.
• Sugar-sweetened beverages and diet soft drinks declined, while fruit drinks increased; the share of unprocessed or minimally processed foods fell from 28.8% (1999) to 23.5%, while ultra-processed foods rose from 61.4% to 67%.

Bottom Line

The core takeaway is to prioritize foods close to their natural form, since Fung argues that processing undermines the body's natural cues for hunger and fullness, and to plan ahead so convenience does not push you toward ultra-processed options.