Appetite, Satiety & Adherence
Does keto reduce hunger, and is it easier or harder to stick to than other diets?
Copper Keto Companion collects the appetite and adherence evidence here, which is dominated by small, short studies that point in different directions. Read together, they suggest ketosis blunts the usual diet hunger rebound modestly, while adherence is no better than other diets.
Contents — 7 entries
- 📄 Do Ketogenic Diets Really Suppress Appetite? (Systematic Review and Meta-Analysis)
- 📄 Ketosis and Appetite-Mediating Hormones After Weight Loss
- 📄 Timeline of Appetite Changes During Weight Loss With a Ketogenic Diet
- 📄 A High-Protein Ketogenic Diet and Hunger in Obese Men Feeding Ad Libitum
- 📄 Plant-Based Low-Fat vs Animal-Based Ketogenic Diet on Ad Libitum Energy Intake
- 📄 Adherence to Ketogenic and Mediterranean Diets in a Crossover Trial (Keto-Med)
- 📄 Atkins, Ornish, Weight Watchers, and Zone Diets for Weight Loss (Randomized Trial)
📄 Do Ketogenic Diets Really Suppress Appetite? (Systematic Review and Meta-Analysis)
Gibson AA, et al. — Obesity Reviews, 2015 · Obesity Reviews, 2015
Copper Keto Companion research surfaced this report because it covers whether ketosis changes appetite during weight loss. This 2015 systematic review found that while people were in ketosis during weight loss they reported less hunger and a lower desire to eat, but the authors stress the absolute changes were small. They frame the effect as preventing the rise in appetite that normally accompanies weight loss, rather than as strong hunger suppression.
What it examines: a meta-analysis of subjective appetite ratings during ketogenic weight loss. Why it's in the Copper Keto Companion research index: a meta-analysis of subjective appetite ratings during ketogenic weight loss.
📄 Ketosis and Appetite-Mediating Hormones After Weight Loss
Sumithran P, et al. — European Journal of Clinical Nutrition, 2013 · Eur J Clin Nutr, 2013
Copper Keto Companion research surfaced this report because it covers a hormonal mechanism for appetite during ketosis. In 39 people who lost about 13% of their weight, the normal post-diet rise in ghrelin, the main hunger hormone, was suppressed while they stayed ketotic, and subjective appetite was lower than after they resumed eating. The sample was modest and there was no separate non-ketogenic comparison group.
What it examines: an interventional study of ghrelin and appetite during and after ketosis. Why it's in the Copper Keto Companion research index: an interventional study of appetite hormones during and after ketosis.
📄 Timeline of Appetite Changes During Weight Loss With a Ketogenic Diet
Nymo S, et al. — International Journal of Obesity, 2017 · Int J Obes, 2017
Copper Keto Companion research surfaced this report because it covers how hunger changes across the phases of a ketogenic diet. In 31 adults with obesity, hunger actually rose in the first few days of the diet, and only later, once ketosis was established, did appetite stop climbing; when ketosis ended at refeeding, hunger and ghrelin rose again. There was no control group, so the findings describe a pattern rather than prove cause.
What it examines: a longitudinal look at how hunger shifts across the phases of a ketogenic diet. Why it's in the Copper Keto Companion research index: a longitudinal study of hunger across the phases of keto.
📄 A High-Protein Ketogenic Diet and Hunger in Obese Men Feeding Ad Libitum
Johnstone AM, et al. — American Journal of Clinical Nutrition, 2008 · Am J Clin Nutr, 2008
Copper Keto Companion research surfaced this report because it covers spontaneous food intake on a ketogenic versus moderate-carb diet. In a randomized crossover of 17 obese men eating freely, the ketogenic phase led to lower spontaneous intake (7.25 versus 7.95 MJ a day), lower hunger, and more weight loss (6.34 versus 4.35 kg) than a moderate-carb phase. Both diets were high in protein (30% of energy), so protein was held constant and the difference tracks the carbohydrate change — though the trial was small, male-only, and ran four weeks per phase.
What it examines: a controlled-feeding crossover of a high-protein ketogenic diet eaten ad libitum. Why it's in the Copper Keto Companion research index: a controlled-feeding crossover of a high-protein ketogenic diet eaten freely.
📄 Plant-Based Low-Fat vs Animal-Based Ketogenic Diet on Ad Libitum Energy Intake
Hall KD, et al. — Nature Medicine, 2021 · Nature Medicine, 2021
Copper Keto Companion research surfaced this report because it covers which diet people spontaneously eat less of, low-fat plant-based or animal-based keto. In a metabolic-ward crossover of 20 adults eating freely, people consumed roughly 550 to 690 kcal a day less on a low-fat plant-based diet than on an animal-based ketogenic diet. The periods were two weeks each and the diets differed in more than carbs, in a tightly controlled inpatient setting.
What it examines: an inpatient test of which diet people spontaneously eat less of. Why it's in the Copper Keto Companion research index: an inpatient crossover of spontaneous intake on plant-based low-fat versus animal-based keto.
📄 Adherence to Ketogenic and Mediterranean Diets in a Crossover Trial (Keto-Med)
Landry MJ, et al. — Nutrients, 2021 · Nutrients, 2021
Copper Keto Companion research surfaced this report because it covers how adherence to keto compares with a Mediterranean diet. In a crossover trial of 40 adults, people followed the ketogenic and Mediterranean diets about equally well while meals were delivered, and adherence to both fell once they shopped for themselves; at follow-up, 85% had drifted back toward Mediterranean-style eating rather than ketogenic. The sample was small and adherence scores are not standardized, so it signals rather than settles the sustainability question.
What it examines: a head-to-head look at how well people stick to keto versus Mediterranean eating. Why it's in the Copper Keto Companion research index: a head-to-head comparison of adherence to keto versus Mediterranean eating.
📄 Atkins, Ornish, Weight Watchers, and Zone Diets for Weight Loss (Randomized Trial)
Dansinger ML, et al. — JAMA, 2005 · pubmed / 15632335
Copper Keto Companion research surfaced this report because it covers how well people actually stick to different diets over a year. In this 2005 JAMA randomized trial assigning 160 adults to the Atkins, Ornish, Weight Watchers, or Zone diets, one-year completion ranged from 50% to 65% across the groups, and the amount of weight lost tracked with self-reported adherence rather than which diet was assigned. It was a modest-sized trial and adherence was self-reported.
What it examines: a randomized trial of one-year adherence and weight loss across four popular diets. Why it's in the Copper Keto Companion research index: a randomized trial on how diet adherence, more than diet type, relates to weight loss.
All 7 sources last verified June 2026.
Frequently Asked Questions
Does keto reduce hunger?
The evidence is mixed and modest. Reviews (Gibson, 2015) find ketosis mainly blunts the hunger rise that normally comes with weight loss, while the best-controlled trial (Hall, 2021) found no hunger advantage and higher intake on keto. This is a research summary, not advice.
Why am I hungrier in the first days of keto?
That pattern is documented. In a 2017 study (Nymo), hunger rose in the first few days and only later, once ketosis was established, stopped climbing.
Is keto easier to stick to than other diets?
Not by the larger evidence. DIETFITS (n=609) and the Cochrane review (61 trials) show no dropout advantage, and a crossover trial (Landry, 2021) found 85% drifted back toward Mediterranean eating afterward.
Do appetite hormones change on keto?
One study (Sumithran, 2013) found the post-diet rise in ghrelin was suppressed while people stayed in ketosis, in 39 participants and without a non-keto comparison group.
More in Keto Research
Educational information only — not medical advice, and not a recommendation to start, stop, or change any diet, supplement, or treatment. Talk to a qualified healthcare professional before making changes. Copper Keto Companion and Copper Sun Content and Creative, LLC are not medical providers.