Habitually Skipping Breakfast Is Associated with the Risk of Gastrointestinal Cancers: Evidence from the Kailuan Cohort Study (2023)
> Results: During a median follow-up of 5.61 (5.18 ~ 6.08) years, 369 incident GI cancer cases were identified. Participants who consumed 1–2 times breakfasts per week exhibited an increased risk of stomach (HR = 3.45, 95% CI: 1.06–11.20) and liver cancer (HR = 3.42, 95% CI: 1.22–9.53). Participants who did not eat breakfast had an elevated risk of esophageal (HR = 2.72, 95% CI: 1.05–7.03), colorectal (HR = 2.32, 95% CI: 1.34–4.01), liver (HR = 2.41, 95% CI: 1.23–4.71), gallbladder, and extrahepatic bile duct cancer (HR = 5.43, 95% CI: 1.34–21.93). In the mediation effect analyses, BMI, CRP, and TyG (fasting triglyceride-glucose) index did not mediate the association between breakfast frequency and the risk of GI cancer incidence (all P for mediation effect > 0.05).
> Conclusions: Habitually skipping breakfast was associated with a greater risk of GI cancers including esophageal, gastric, colorectal, liver, gallbladder, and extrahepatic bile duct cancer.
There is actually a lot more evidence in favor of breakfast if you follow the related links on the aforementioned PMID page.
Meanwhile, here are some more studies showing a benefit of breakfast. It is certainly possible that there are confounding factors, but the relative risks of ignoring the data are too high.
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Meta-Analysis of Relation of Skipping Breakfast With Heart Disease (2019) (PMID: 31326073)
> The primary meta-analysis combining HRs for Q1 (first quartile, most skipping breakfast) versus Q4 (fourth quartile, least skipping breakfast) from 3 studies together with other HRs/ORs demonstrated that skipping breakfast was associated with the significantly increased risk of heart disease (pooled HR/OR 1.24; 95% CI 1.09 to 1.40; p = 0.001). In sensitivity analyses combining HRs for Q2 (second quartile, second most skipping breakfast) versus Q4 or HRs for Q3 (third quartile, second least skipping breakfast) versus Q4 from 3 studies together with other HRs/ORs, the association of skipping breakfast with the increased risk of heart disease in the primary meta-analysis was confirmed. In conclusion, skipping breakfast is associated with the increased risk of heart disease.
Association between skipping breakfast and risk of cardiovascular disease and all cause mortality: A meta-analysis (2020) (PMID: 32085933)
> Results: Skipping breakfast was associated with elevated risk of cardiovascular disease (relative risk 1.22 95% confidence interval 1.10-1.35) and all cause mortality (relative risk 1.25 95% confidence interval 1.11-1.40) compared with eating breakfast regularly.
> Conclusion: Skipping breakfast increases the risk of cardiovascular disease and all cause mortality. Eating breakfast regularly may promote cardiovascular health and decrease all cause mortality.
> The health benefit of breakfast has now been completely debunked by a new systematic review and meta-analysis of 11 randomised trials that investigated the impact of skipping breakfast on weight and metabolic rate. The studies vary widely in duration and quality, and seven looked at changes in weight as well as changes in energy usage. Their conclusion is the same as in recent reviews that have been largely ignored, namely, there is no evidence to support the claim that skipping meals makes you put on weight or adversely reduces your resting metabolic rate.
I found a bunch of others, but in any case, do whatever works for you, is my advice.
It's also not unusual for science to regularly swing between opposing viewpoints on dietary matters every decade or so. There are certainly many examples of this in my own lifetime.
I am linking about cancer and cardiovascular disease and mortality, whereas you're linking about weight. Weight is something that anyone can trivially measure and then adjust one's lifestyle accordingly. The others are not. The outcomes for cancer and CVD hold significantly more weight for obvious reasons.
It is not at all a fact, though it was widely disbursed as one for many decades in the 20th century. In fact, recent studies have proven quite the opposite, that it has almost no effect on health or mortality if someone eats or skips breakfast. There are a few exceptions, like people who are at risk of heart failure should not skip meals, but for the vast majority of the public, skipping breakfast actually has proven to have some benefits.
Your claim is in direct contradiction to the current state of the literature. The scientific community is in consensus around the fact that late meal timing is damaging to metabolic health. Meal timing should be aligned to the body's circadian clock, which is the most active early in the day and becomes more dormant as the day progresses. People who delay caloric intake later into the day and into the evening have worse glucose control (a meal eaten in the evening can carry twice the glycemic impact as it does compared to in the morning). They also have increased triglycerides, increased levels of obesity, markers of oxidative stress, increased gut microbiota and hormone dysregulation, etc [1].
As a system, our bodies are more active in the morning than they are in the evening, which most people can identify with, so this shouldn't be surprising. It's not clear if, by skipping breakfast and decreasing caloric intake, but thereby delaying the feeding window, a beneficial effect for some individuals exists. Most of the data points in the opposite direction, but maybe, for the extremely metabolically fit individual who shovels glucose into cells like a snowplow, it's less problematic? I'm just positing, but we don't have good evidence for that. What we do have evidence for is that those who engage in IF but do it with a delayed eating schedule generally have worse health outcomes.
Some references:
[1] "Late eating decreased glucose tolerance, resting energy expenditure, and carbohydrate oxidation as compared to early eating. Besides, the cortisol profile was blunted for late eating as compared to early eating, similarly to that found under acute stress situations [11]. Eating late also affected the daily rhythms of peripheral temperature, towards a similar pattern to that found in overweight/obesity women which was related to metabolic alterations"
"Dietary patterns that feature meal timing outside of the regular daytime hours can contribute to circadian disruption as food is metabolised in opposition to internal daily rhythms and can feedback on the timekeeping mechanisms setting these rhythms. Epidemiological evidence examining the impact of late meal timing patterns is beginning to suggest that eating at night increases the risk of weight gain over time"
Eating too late is unhealthy, but that is not the same as skipping breakfast. Eating too late or too early both have negative results.
The first paper says:
"Unlike lunch and dinner, which are recommended early in the day, it has been proved that to have breakfast too early may be deleterious due to melatonin levels, which may still be high in the early morning."
The second paper references a 12 week randomized controlled trial that shows that it is good to skip breakfast, eating within a time restricted window (12:00 - 20:00).
Personally I usually aim for a TRE of 12:00 - 17:00 and that has worked well for me over the past 15 years. Skip breakfast, early dinner, as recommended by those papers. I feel lethargic and tired if I eat breakfast. Listen to your body.
The first paper is not making the claim that eating breakfast is unhealthy—just that you don't want to eat right as you wake up. These are different things. The second paper references two different studies where, when people at more than 33% or 50% of their calories for dinner, they were more likely to be obese.
I agree that eating from noon to 5pm can be an optimal eating window, but you are going to have to eat a large amount of food at noon and a relatively small meal at an early dinner if you're not eating breakfast. That's possible for some people; but I think the vast majority of people prefer to eat 3 meals a day and are better off consuming the bulk of the calories earlier. My personal experience with people that skip breakfast: they tend to have a moderately large lunch and a moderately large dinner, which is probably not optimal. And that's because when delaying food intake in the morning, they tend to grow relatively hungrier as the day progresses.
One thing the papers show is there is a natural rhythm of hormones and metabolism, which is adaptable to some extent, and you just need to listen to your body. But if you are addicted to sugar / excessive carbs, and don't exercise, then playing around with meal times is just rearranging deck chairs on the Titanic. Your body signals are malfunctioning.
Personally I have found a moderate size lunch and larger dinner, with a snack or two before or after dinner, is just perfect. Most people don't need three full meals a day. With moderate carbs I never go into a food coma. Worst is eating a large breakfast which makes you feel tired just when you are starting the day and trying to be productive.
If you have trained your body to burn fat (moderate or low carb diet) then you will be running on fat reserves efficiently through the day until the first meal.
Yeah, I agree with your assessment here. The statement "breakfast is the most important meal of the day" is a bit hyperbolic given all of the nuances introduced. But, still, at the end of the day, clinical recommendations have to be made; and physicians have to talk to patients in a very straightforward and un-nuanced manner. I still think the adage, breakfast being the most important meal of the day, can ring true for most people; as placeholder advice to "try to eat more earlier". The statements are not synonymous as you've pointed out; but my goal was to plant a flag because I think most people throw the baby out with the bathwater when they decide to skip breakfast (i.e they tend to consume too many calories too late).
Fifteen year olds are still growing, in the anabolic phase, so they should eat more often if they have the appetite. Forget it when you are a fully grown adult.
