The Sensational 2024 Intermittent Fasting Study—Taking a Closer Look

Imagine my shock when I saw a 2024 intermittent fasting study, claiming that people who eat within an 8-hour window have a 91% higher risk of dying from cardiovascular disease. As someone who’s been living the 18:6 fasting life for years (even while on vacation) I got a little panicky! I had to see the study myself to see how they came up with this headline.

🔍 What the Study Actually Did

• Tracked ~20,000 U.S. adults (average age 49, ~73% White, 11% Hispanic, 8% Black; evenly split men/women)
• Followed participants from 2003-2018; 2 dietary recalls in year 1, followed for a median of 8 to 17 years
• Included people with cardiovascular disease and/or cancer as well as smokers and drinkers
• Did not control for lifestyle factors (diet quality, sleep, exercise, etc.)
• Admits it’s preliminary research—not yet peer-reviewed (and at the time of this posting, still not)

Why 2003 Raises a Giant Red Flag for Intermittent Fasting Research

Back in 2003, intermittent fasting—especially the kind where you eat in a specific window like 16:8—wasn’t even on the radar. So if someone in this study was eating within 8 hours, it probably wasn’t on purpose. Maybe they were juggling school, working a crazy shift, recovering from a wild night out, or just had one of those chaotic days where you realize at 4 p.m. that you never ate lunch. These weren’t intentional fasters—they were just living their lives. And yet the study treats every short eating window like a deliberate health choice.

Confounding Factors Left Unchecked

That’s not all. The researchers didn’t filter out shift workers (around 16% of the U.S. population), diabetics (roughly 12% of the U.S. population), or people with chronic health conditions—all of whom already face a higher risk for heart disease. In fact, a 2016 meta-analysis (Kecklund & Axelsson, 2016) specifically linked shift work to increased heart disease risk. So this wasn’t a clean group of healthy individuals following a structured fasting plan. When you take a closer look, if anything, it seems more likely that the study was measuring the impact of chaotic schedules, not the effects of intermittent fasting.

The Data Recall Problem

Another major flaw—common to most nutrition studies that rely on self-reporting—is the faulty accuracy of food recall. Asking people to remember exactly what and when they ate over the past 24 hours is notoriously unreliable, not only because of murky memories but also because some people omit snacks or lie (who wants to admit to that late-night cookie?) This study was no exception. Even the authors acknowledged that participants’ responses might not have reflected their usual eating habits.

Association ≠ Causation

Even experts have stressed this: the findings are associational, not proof of cause and effect. In other words, the higher risk of heart disease might have less to do with when people ate—and more to do with who was eating that way. Think: stress, chaotic work hours, underlying health conditions. Those factors could’ve played a much bigger role than the eating window itself.

What About the Positive Evidence for Intermittent Fasting?

This one study shouldn’t be enough to derail your fasting lifestyle. There’s strong, peer-reviewed evidence that time-restricted eating and fasting can support cellular repair, improve lipid profiles, balance blood sugar, and even lower inflammation and blood pressure. Pretty impressive for something that doesn’t involve counting a single calorie or giving up cake!

💧 1. Lower blood pressure & inflammation

A meta-analysis and clinical evidence show that intermittent fasting can significantly reduce blood pressure and markers of inflammation:

• A review in Verywell Health (2025) found that fasting positively affects blood pressure, inflammation, cholesterol, and blood sugar, and highlights a study in prediabetic men where fasting reduced systolic BP by ~11 mmHg and diastolic by ~10 mmHg.
• Research published by the Intermountain Healthcare Institute demonstrated that intermittent fasting prompts an anti-inflammatory response via increased levels of galectin‑3 (2021).

🩸 2. Improves glucose & cholesterol markers

Multiple meta-analyses have confirmed that IF enhances blood sugar control and lipid profile:

• A meta-review (2025) evaluating 50 peer-reviewed studies reported clear improvements in glucose metabolism and insulin sensitivity, including better HDL/LDL ratios and lower HbA1c.
• Another meta-analysis (2025) involving patients with type 2 diabetes showed significant reductions in HbA1c, fasting plasma glucose, LDL, total cholesterol, blood pressure, and weight.

🌀 3. Supports cellular repair & metabolic health

Evidence indicates intermittent fasting triggers biological processes that support cellular rejuvenation:

• An MIT study (2024) showed fasting activates stem cells and mTOR pathways for intestinal repair after refeeding.
• Research from Institut Pasteur (2024) indicates IF stimulates autophagy (the body’s cellular “cleanup” system), which helps remove damaged proteins—a benefit linked to longevity and disease resistance.
• And if you want to understand how fasting influences your fullness hormones, read this next

So. . .Should You Ditch Your 16:8 Window? I’m Not

So what’s the takeaway? I’m not saying that time-restricted eating does or doesn’t lead to cardiovascular disease. I’m saying, don’t let headlines scare you into second-guessing a lifestyle that’s actually working for you, especially if you’re seeing and feeling results. This study doesn’t prove that time-restricted eating is dangerous—it shows that context, intention, and methodology matter a lot. It’s always smart to stay informed, but even smarter to look beyond the sensational headlines.