A very good summary article of lots of little tidbits about eating and issues.
Eating fast leads to a bunch of problems. While eating slow leads to lower calories for those not-so-heavy, it may not make any difference if you’re already obese. But eating late (evening or lots later in the day) has substantially increased risks of weight gain. Even time restricted eating is better if you make your eating window earlier in the day.
The article even suggests a truly radical concept: Eat only if you are hungry, don’t if you’re not! RADICAL!
Speedy Eating and Late-Night Meals May Take a Toll on Health
You are what you eat, as the adage goes. But a growing body of evidence indicates that it's not just what and how much you eat that influence your health. How fast and when you eat also play a role.
Research now indicates that these two factors may affect the risk for gastrointestinal problems, obesity, and type 2 diabetes (T2D). Because meal timing and speed of consumption are modifiable, they present new opportunities to change patient behavior to help prevent and perhaps address these conditions.
Not So Fast
Most people are well acquainted with the short-term gastrointestinal effects of eating too quickly, which include indigestion, gas, bloating, and nausea. But regularly eating too fast can cause long-term consequences.
Obtaining a sense of fullness is key to staving off overeating and excess caloric intake. However, it takes approximately 20 minutes for the stomach to alert the brain to feelings of fullness. Eat too quickly and the fullness signaling might not set in until you've consumed more calories than intended. Research links this habit to excess body weight.
The practice also can lead to gastrointestinal diseases over the long term because overeating causes food to remain in the stomach longer, thus prolonging the time that the gastric mucosa is exposed to gastric acids.
A study of 10,893 adults in Korea reported that those with the fastest eating speed (< 5 min/meal) had a 1.7 times greater likelihood of endoscopic erosive gastritis than those with the slowest times (≥ 15 min/meal). Faster eating also was linked to increased risk for functional dyspepsia in a study involving 89 young-adult female military cadets in Korea with relatively controlled eating patterns.
On the extreme end of the spectrum, researchers who performed an assessment of a competitive speed eater speculated that the observed physiological accommodation required for the role (expanding the stomach to form a large flaccid sac) makes speed eaters vulnerable to morbid obesity, gastroparesis, intractable nausea and vomiting, and the need for gastrectomy.
The risk for metabolic changes and eventual development of T2D also appear to be linked to how quickly food is consumed.
Two clinical studies conducted in Japan — a cohort study of 2050 male factory workers and a nationwide study with 197,825 participants — identified a significant association between faster eating and T2D and insulin resistance. A case-control study involving 234 patients with new onset T2D and 468 controls from Lithuania linked faster eating to a greater than twofold risk for T2D. And a Chinese cross-sectional study of 7972 adults indicated that faster eating significantly increased the risk for metabolic syndrome, elevated blood pressure, and central obesity in adults.
Various hypotheses have been proposed to explain why fast eating may upset metabolic processes, including a delayed sense of fullness contributing to spiking postprandial glucose levels, lack of time for mastication causing higher glucose concentrations, and the triggering of specific cytokines (eg, interleukin-1 beta and interleukin-6) that lead to insulin resistance. It is also possible that the association is the result of people who eat quickly having relatively higher body weights, which translates to a higher risk for T2D.
However, there's an opportunity in the association of rapid meal consumption with gastrointestinal and metabolic diseases, as people can slow the speed at which they eat so they feel full before they overeat.
A 2019 study in which 21 participants were instructed to eat a 600-kcal meal at a "normal" or "slow" pace (6 minutes or 24 minutes) found that the latter group reported feeling fuller while consuming fewer calories.
This approach may not work for all patients, however. There's evidence to suggest that tactics to slow down eating may not limit the energy intake of those who are already overweight or obese.
Patients with obesity may physiologically differ in their processing of food, according to Michael Camilleri, MD, consultant in the Division of Gastroenterology and Hepatology at Mayo Clinic in Rochester, Minnesota.
"We have demonstrated that about 20%-25% of people with obesity actually have rapid gastric emptying," he told Medscape Medical News. "As a result, they don't feel full after they eat a meal and that might impact the total volume of food that they eat before they really feel full."
The Ideal Time to Eat
It's not only the speed at which individuals eat that may influence outcomes but when they take their meals. Research indicates that eating earlier in the day to align meals with the body's circadian rhythms in metabolism offers health benefits.
"The focus would be to eat a meal that syncs during those daytime hours," Collin Popp, PhD, MS, RD, a research scientist at the NYU Grossman School of Medicine in New York, told Medscape Medical News. "I typically suggest patients have their largest meal in the morning, whether that's a large or medium-sized breakfast, or a big lunch."
A recent cross-sectional study of 2050 participants found that having the largest meal at lunch protected against obesity (odds ratio [OR], 0.71), whereas having it at dinner increased the risk for obesity (OR, 1.67) and led to higher body mass index.
Consuming the majority of calories in meals earlier in the day may have metabolic health benefits, as well.
A 2015 randomized controlled trial involving 18 adults with obesity and T2D found that eating a high-energy breakfast and a low-energy dinner leads to reduced hyperglycemia throughout the day compared with eating a low-energy breakfast and a high-energy dinner.
Time-restricted eating (TRE), a form of intermittent fasting, also can improve metabolic health depending on the time of day.
A 2023 meta-analysis found that TRE was more effective at reducing fasting glucose levels in participants who were overweight and obese if done earlier rather than later in the day. Similarly, a 2022 study involving 82 healthy patients without diabetes or obesity found that early TRE was more effective than mid-day TRE at improving insulin sensitivity and that it improved fasting glucose and reduced total body mass and adiposity, while mid-day TRE did not.
A study that analyzed the effects of TRE in eight adult men with overweight and prediabetes found "better insulin resistance when the window of food consumption was earlier in the day," noted endocrinologist Beverly Tchang, MD, an assistant professor of clinical medicine at Weill Cornell Medicine with a focus on obesity medication.
Patients May Benefit From Behavioral Interventions
Patients potentially negatively affected by eating too quickly or at late hours may benefit from adopting behavioral interventions to address these tendencies. To determine if a patient is a candidate for such interventions, Popp recommends starting with a simple conversation.
"When I first meet patients, I always ask them to describe to me a typical day for how they eat — when they're eating, what they're eating, the food quality, who are they with — to see if there's social aspects to it. Then try and make the recommendations based on that," said Popp, whose work focuses on biobehavioral interventions for the treatment and prevention of obesity, T2D, and other cardiometabolic outcomes.
Tchang said she encourages her patients to be mindful of hunger and fullness cues.
"Eat if you're hungry; don't force yourself to eat if you're not hungry," she said. "If you're not sure whether you're hungry or not, speak to a doctor because this points to an abnormality in your appetite-regulation system, which can be helped with GLP-1 [glucagon-like peptide 1] receptor agonists."
Adjusting what patients eat can help them improve their meal timing.
"For example, we know that a high-fiber diet or a diet that has a large amount of fat in it tends to empty from the stomach slower," Camilleri said. "That might give a sensation of fullness that lasts longer and that might prevent, for instance, the ingestion of the next meal."
Those trying to eat more slowly are advised to seek out foods that are hard in texture and minimally processed.
A study involving 50 patients with healthy weights found that hard foods are consumed more slowly than soft foods and that energy intake is lowest with hard, minimally processed foods. Combining hard-textured foods with explicit instructions to reduce eating speed has also been shown to be an effective strategy. For those inclined to seek out technology-based solution, evidence suggests that a self-monitoring wearable device can slow the eating rate.
Although the evidence is mounting that the timing and duration of meals have an impact on certain chronic diseases, clinicians should remember that these two factors are far from the most important contributors, Popp said.
"We also have to consider total caloric intake, food quality, sleep, alcohol use, smoking, and physical activity," he said. "Meal timing should be considered as under the umbrella of health that is important for a lot of folks."