Intermittent fasting isn’t appetizing for everyone

Intermittent fasting isn’t appetizing for everyone

June 18, 2026 discoverhiddenusacom Health

Intermittent fasting is a dietary schedule that alternates between fasting and eating, which Nicole O’Neill, a registered dietitian with OSF HealthCare, says varies in effectiveness based on the individual. While it can create a calorie deficit for weight loss, O’Neill warns it is not recommended for pregnant women, minors, or those with Type 1 diabetes.

How does intermittent fasting work for weight loss?

Intermittent fasting restricts calories by limiting the time a person spends eating during the day. According to O’Neill, this creates a calorie deficit that can lead to weight loss because the person only eats twice daily.

Common methods used to achieve this include:

  • 16:8: Fasting for 16 hours and eating during an eight-hour window, such as noon to 8 p.m.
  • 14:10: A 14-hour fast with a 10-hour eating window.
  • 5:2: Eating normally for five days a week and consuming significantly reduced calories on two non-consecutive days.
Did You Know? While the practice has existed for a long time, the diet gained significant popularity in the early 2000s and saw a further boost in 2018 after celebrities Jennifer Aniston and Hugh Jackman shared their success stories.

What are the risks and side effects of fasting?

Long periods without food can lead to physical and cognitive impairments. O’Neill notes that some individuals experience an increase in anxiety, fatigue, and daytime sleepiness.

Cognitive issues, described as “brain fog,” may result in people failing to finish tasks, thoughts, or words. There is also a risk of failing to consume enough fiber, protein, vitamins, and minerals.

Expert Insight: The tension between the simplicity of calorie restriction and the risk of “brain fog” or nutrient deficiency suggests that a one-size-fits-all approach to fasting is unsustainable. The shift toward GLP-1 medications indicates a broader move toward pharmacological interventions over behavioral fasting schedules for some users.

Who should avoid intermittent fasting?

Certain populations face higher risks when skipping meals. O’Neill states that intermittent fasting is not recommended for individuals under the age of 18, those with Type 1 diabetes, and women who are pregnant or breastfeeding.

Discussing Intermittent Fasting | OSF HealthCare

For others, skipping breakfast may be counterproductive. O’Neill explains that waiting until noon to eat can make some people so hungry they become “out of control” during their eating window, potentially consuming more calories than if they had eaten three standard meals.

What happens next for those trying this diet?

Individuals may need to work with a dietitian to determine if a specific eating schedule fits their lifestyle and personality. O’Neill recommends eating two to three hours after waking to maintain energy levels.

What happens next for those trying this diet?

Some people may transition away from fasting entirely. O’Neill notes that the emergence of GLP-1 weight loss medications has already replaced intermittent fasting for some users.

Frequently Asked Questions

What are the most common intermittent fasting methods?
The most common methods are 16:8 (16-hour fast), 14:10 (14-hour fast), and 5:2 (two days of reduced calories per week).

Who is prohibited from using intermittent fasting?
According to Nicole O’Neill, it is not recommended for people under 18, those with Type 1 diabetes, and individuals who are pregnant or breastfeeding.

Can intermittent fasting cause mental clarity issues?
Yes, O’Neill reports that some users experience “brain fog,” which can manifest as an inability to finish words, thoughts, or tasks.

Have you ever tried a scheduled eating plan to manage your health?

, , , , , , , ,