Calorie density and weight loss: what 14 plant based experts say

• Agree 10
• Partly 3
• Disagree 1
• No statement 0

At a glance

What each expert says

• Walter Kempner

  MD

  Disagrees

  Kempner's weight-loss program cut calories directly: 400 to 800 a day at first and always under 1,000, with daily supervision. His paper calls calorie reduction the cornerstone, and his successor Frank Neelon later said on McDougall's channel that calories do count.

  Evidence: Case series, selected for success

  • Kempner 1975, Archives of Internal MedicineStudy
  • Frank Neelon on McDougall's channel (2022) at 58:11Someone else speaking

• Nathan Pritikin

  Engineer, no medical degree

  Agrees

  The center teaches eating to comfortable fullness from low-density foods, since people tend to eat about the same weight of food from day to day. On a plateau, though, it advises eating fewer calories or exercising more.

  Evidence: Case series (uncontrolled residential programs)

  • Pritikin center: new science on losing weightOrganization page
  • Pritikin center: plateau tipsOrganization page

• John McDougall

  MD

  Agrees

  McDougall told people to fill up on starches and vegetables without counting or weighing anything. His explanation combined calorie dilution with his view that dietary fat turns into body fat far more easily than carbohydrate does.

  Evidence: Case series (short, residential)

  • McDougall on video (2023) at 1:35:15
  • McDougall Program checklist (unsigned)Organization page

• Dean Ornish

  MD

  Agrees

  On camera Ornish says calories count, but argues that cutting fat lets you eat the same amount of food with far fewer calories: change the kind of food, not the amount. His program's written guidelines add portion control for weight loss, which he does not say himself in his videos.

  Evidence: RCT for heart outcomes; modest results in independent weight trials

  • Ornish on obesity (2012) at 0:53
  • Ornish on NBC Today (2012) at 3:41
  • Ornish program nutrition guidelines (archived)Organization page

• T. Colin Campbell

  PhD

  Partly agrees

  Campbell argues that people on low-fat plant diets can eat more calories and still weigh less. He credits mostly physical activity, plus a possible extra calorie burn on low-protein diets seen in rats, and calls lasting calorie restriction close to impossible for most people.

  Evidence: Ecological and animal studies

  • Campbell talk (2003) at 30:53
  • Same talk, on calorie restriction at 1:02:15
  • Campbell and Chen 1999, Toxicological SciencesStudy

• Neal Barnard

  MD

  Agrees

  PCRM gives low energy density as one of two reasons its low-fat vegan diet works, the other being more calories burned after meals. Its trial volunteers had no calorie limits yet ate less.

  Evidence: Randomized controlled trials

  • PCRM weight-loss pageOrganization page
  • Barnard 2005, randomized trialStudy

• Hana Kahleova

  MD, PhD

  Partly agrees

  In her 2020 trial, people on an unrestricted low-fat vegan diet ate about 355 fewer calories a day than controls and burned more after meals, and the authors credit both. Inside the trial the after-meal burn did not track weight change, so eating less explains most of the result.

  Evidence: Randomized controlled trials, plus cohort data

  • Kahleova 2020, JAMA Network OpenStudy

• Alan Goldhamer

  DC (chiropractor, not a medical doctor)

  Agrees

  Goldhamer teaches a ladder from salad, about 100 calories per pound, to oil, about 4,000, and says losing weight means removing the concentrated processed foods. He adds that salt, oil and sugar push people to overeat through the brain's reward system.

  Evidence: Case series (single-arm clinic studies)

  • Goldhamer talk (2018) at 40:10
  • Same talk, on processed foods at 1:02:23

• Doug Lisle

  PhD

  Agrees

  Lisle says you never need to eat less than your hunger asks: make the diet less calorie-dense and the body loses weight on its own. His explanation: rich food, fat most of all, gets past the signals that normally tell the stomach it is full.

  Evidence: No studies of his own; clinical experience

  • Lisle lecture at 59:43
  • Same lecture, density by food at 45:05

• Jeff Novick

  MS, RDN (registered dietitian)

  Agrees

  Calorie density is Novick's whole method, with a number scale: eat freely below roughly 300 to 400 calories per pound, moderately up to 800, limit up to 1,800 and extremely limit above that. He rejects calorie counting outright.

  Evidence: No studies of his own; summarizes feeding studies

  • Novick: the calorie density approach
  • Novick talk (2010) at 1:30
  • Novick: how to count calories

• Chef AJ

  Chef and TV host, no medical credential

  Agrees

  Chef AJ's program opens the day with a pound or more of non-starchy vegetables, eats foods in order of rising density and stops at comfortably full. She says calories do count, but that counting them does not last.

  Evidence: Personal story and program reports; no trials

  • Chef AJ talk (2016) at 5:00
  • Weight Loss Wednesday (2016), vegetables first at 19:20
  • Weight Loss Wednesday (2016), on calories at 15:53

• Michael Greger

  MD

  Agrees

  Greger's weight-loss advice rests on low calorie density, fiber and whole plant foods whose cell walls are intact, with low-density foods eaten before meals. He says no counting is needed, yet notes his Daily Dozen lands at roughly 1,200 to 1,500 calories.

  Evidence: Reviews of other people's trials

  • NutritionFacts: losing weight eating more food
  • Greger 2020 review, Am J Lifestyle MedStudy
  • NutritionFacts: Daily Dozen put to the test

• Rip Esselstyn

  Former firefighter and triathlete, no medical credential

  Agrees

  Rip says calorie-counting diets do not last and that generous amounts of unprocessed plant food do the work. PLANTSTRONG's site explains weight loss as calorie density: skip liquid calories, high-fat foods and refined grains.

  Evidence: Uncontrolled pilot and event data

  • Engine 2 keynote (2009) at 1:13:31
  • PLANTSTRONG blog: calorie densityOrganization page

• Peter Rogers

  MD

  Partly agrees

  Rogers does not count calories and has people eat vegetables first to stretch the stomach. His main explanation, though, is that dietary fat is stored as body fat, along with oils, hormone-like chemicals and stress.

  Evidence: No studies of his own; population and mechanism arguments

  • Prevent and Reverse Obesity, part 17 (2025) at 3:30
  • Same video, on fat at 0:12

What the evidence says

• In PCRM's 16-week trial, people on a low-fat vegan diet with no calorie limit ate roughly 490 fewer calories a day on their own and lost about 5.9 kg.
  • Kahleova 2020, JAMA Network OpenStudy
• When PCRM compared a vegan diet with portion-controlled eating over 20 weeks, the difference in weight loss was not statistically significant.
  • Barnard 2018, randomized trialStudy
• The only independent long-term trial of an unrestricted whole-food plant based diet (BROAD, New Zealand, 2017) reported about 11.5 kg lost at 12 months, but only 23 of 33 participants were followed up.
  • Wright 2017, BROAD trialStudy

More topics

• Nuts and seedsNuts and seeds should be cut out or strictly limited for weight loss.
• OilAdded oil should be cut out completely for weight loss.