Fasting but Not Losing Weight? What Trials Say About the Plateau

In 30 seconds

Trials have not studied intermittent-fasting plateaus directly, so they cannot say why your weight stalled. In longer trials, fasting diets and daily calorie restriction led to similar, modest weight loss, and adherence often fell. No evidence cited here shows that switching schedules restarts weight loss.

• Trials have not studied weight-loss plateaus during intermittent fasting directly.
• In trials of 24 weeks or more, fasting diets and daily calorie restriction led to similar weight loss compared with unrestricted eating.
• Adherence often fell in longer trials, and review authors name declining adherence and metabolic adaptation as possible limits with any diet.
• No trial cited here shows that switching fasting schedules restarts weight loss.

Why did my weight stall?

Trials did not measure plateaus. What they show is how average weight changed with trial length.

Trial evidence does not study plateaus directly. In longer fasting trials, adherence often fell, and the authors of a large review note that declining adherence and metabolic adaptation could limit sustained weight loss with any diet, not only fasting.Source 11

Differences between approaches faded in longer trials; average loss stayed modest.

In trials of 24 weeks or more, fasting diets and daily calorie restriction produced similar weight loss compared with unrestricted eating; very few trials lasted a year or longer.Source 11

Should I change my schedule?

The evidence here cannot tell you whether that helps, and in energy-matched trials adding a time window rarely added weight loss.

No trial evidence cited here shows that switching fasting schedules restarts weight loss, and no single schedule was best for everyone; in 7 energy-matched trials, most found no extra benefit from adding time restriction.Source 11Source 22

What did the trials find?

All fasting diets and daily calorie restriction lowered weight compared with unrestricted eating. Only alternate-day fasting lost more than calorie restriction (about 1.3 kg, below the authors' 2 kg threshold for importance), and only in shorter trials.Source 11

A systematic review found that most of 7 trials (579 adults with overweight or obesity) showed no extra benefit from adding time restriction to the same calorie reduction; 2 trials found greater weight loss.Source 22

Who should get advice first?

These are averages from trials with different definitions, lengths and adherence, so they cannot predict when, or whether, one person’s weight will stall.

A plateau is never a reason to lengthen a fast or adjust a medicine on your own.

People with diabetes or who take glucose-lowering medicines should plan any change to fasting with a clinician because medicines may need adjusting, and anyone should talk with a healthcare provider before significant changes to their eating pattern.Source 33Source 55

Talk to a qualified health professional before fasting if you are pregnant or breastfeeding, under 18, living with or recovering from an eating disorder, have diabetes, take insulin or a medicine affected by meal timing, are an older adult, or are acutely ill. Do not change the dose or timing of any medicine without your clinician. See Blimbi’s safety guide.

Related guides

• Intermittent Fasting for Weight Loss: Realistic Results

  Intermittent fasting for weight loss shows modest average losses, about 4.6 kg more than control over 12 months, similar to daily calorie restriction.

• Does Intermittent Fasting Reduce Belly Fat? What Reviews Show

  Does intermittent fasting reduce belly fat? No review shows it beats calorie-matched diets for belly fat; trials do show lower body weight.

• Intermittent Fasting and Keto Diet: Can You Combine Them?

  Can you combine intermittent fasting and a keto diet? What one 3-month trial found, why the mix is untested, and who should ask a clinician first.

• Vitamins and Supplements While Fasting: Do They Break It?

  Taking vitamins and supplements while fasting: sugary gummies and protein powders end a strict fast, plain tablets are a grey area. Magnesium, creatine and medicines.

Frequently asked questions

Why did my weight stall during intermittent fasting?

Trials cannot answer that for one person, because they did not study plateaus directly. In longer trials adherence often fell, and review authors suggest that declining adherence and metabolic adaptation could limit sustained weight loss with any diet, not only fasting.Source 11

Should I change my fasting schedule if I hit a plateau?

No trial evidence here shows that switching schedules restarts weight loss, and no single schedule was best for everyone. If you have diabetes or take glucose-lowering medicines, do not lengthen your fast without your clinician.Source 11Source 33

Is intermittent fasting uniquely effective for long-term weight loss?

No. In trials of 24 weeks or more, fasting diets and daily calorie restriction produced similar weight loss compared with unrestricted eating, and most energy-matched trials found no extra benefit from adding time restriction. Very few trials lasted a year or longer.Source 11Source 22

Sources

1. 1

   Intermittent fasting strategies and their effects on body weight and other cardiometabolic risk factors: systematic review and network meta-analysis of randomised clinical trialsZhila Semnani-Azad et al. BMJ, June 18, 2025.DOI: 10.1136/bmj-2024-082007 · PMID: 40533200Systematic review and meta-analysis

2. 2

   Does time-restricted eating add benefits to calorie restriction? A systematic reviewArmin Ezzati et al. Wiley, April 1, 2024.DOI: 10.1002/oby.23984 · PMID: 38383703Systematic review and meta-analysis

3. 3

   Fasting Safely with DiabetesMartin M. Grajower. National Institute of Diabetes and Digestive and Kidney Diseases, August 26, 2020.Official guidance

4. 4

   Low blood sugar (hypoglycaemia)NHS. NHS, August 3, 2023.Official guidance

5. 5

   Calorie restriction and fasting diets: What do we know?National Institute on Aging. National Institute on Aging, August 14, 2018.Official guidance