Can you eat all you want of whole foods and lose weight?

The claim checked: You can eat as much real food as you want and still lose weight Hear it at 30:43

What do the studies say?

Strong consensus for

All four studies agree. In an inpatient trial at the NIH, 10 men and 10 women ate as much as they wanted. They lost 0.9 kg on the unprocessed diet and gained 0.9 kg on the ultra-processed diet. A UK trial found both diets led to weight loss over 8 weeks, with more on the minimally processed diet. These trials were small and short.

Computed from 4 studies that test this point, each judged by two readers, in full. 4 more studies are waiting for a full read and do not count yet.

What was said on the podcast?

“And again, you can eat an unlimited amount of food and you won't gain weight. You'll lose weight. And it always sounds crazy, but the science is so clear on this. My colleague David Ludwig at Harvard has published on this over and over again.”

Mark Hyman, The Doctor's Farmacy · If I Could Only Do ONE Thing to Treat Chronic Disease, This Would Be It · 30:43 on YouTube

Episode check Modern wheat has much more gluten, the episode says. Seven of eight studies disagree. 5 claims checked against 36 studies · 10 chapters not checked yet See the whole episode →

The point checked Strong consensus for

Eating as much as you want of unprocessed whole food leads to weight loss without counting calories

Agree 4

controlled trial · 2019 · landmark

“Figure 3A illustrates that participants gained 0.9±0.3 kg (p=0.009) during the ultra-processed diet and lost 0.9±0.3 kg (p=0.007) during the unprocessed diet.”

Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake. Cell Metab
Who: 10 male and 10 female weight-stable adults aged mean 31.2, BMI 27, inpatients at the NIH Clinical Center
PMID 31105044

controlled trial · 2017 · landmark

“To the best of our knowledge, there are no randomised controlled trials that have achieved a greater average weight loss over a 6- or 12-month period, without mandating regular exercise or restricting total caloric intake.”

The BROAD study: A randomised controlled trial using a whole food plant-based diet in the community for obesity, ischaemic heart disease or diabetes. Nutr Diabetes
Who: Adults aged 35-70 with overweight or obesity and type 2 diabetes, ischaemic heart disease, hypertension or hypercholesterolaemia, from a general practice in Gisborne, New Zealand
PMID 28319109

controlled trial · 2025 · landmark

“In conclusion, ad libitum 8-week MPF and UPF diets meeting UK dietary guidance resulted in weight loss, but with significantly greater reductions in weight on the MPF than on the UPF diet.”

Ultraprocessed or minimally processed diets following healthy dietary guidelines on weight and cardiometabolic health: a randomized, crossover trial. Nat Med
Who: 55 UK adults with BMI 25 to under 40 and habitual UPF intake of at least 50% of energy (91% female, mean age 43)
PMID 40760353

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controlled trial · 2016

“In terms of body composition, we have shown a 4.3% reduction in body weight and 3.8% reduction in waist circumference on a Paleolithic diet.”

Cardiovascular, Metabolic Effects and Dietary Composition of Ad-Libitum Paleolithic vs. Australian Guide to Healthy Eating Diets: A 4-Week Randomised Trial. Nutrients
Who: healthy women aged 18-70 in Western Australia (mean age 47, BMI 27)
PMID 27223304

Partly agree 0

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Disagree 0