番茄社区

Dieters are often told to eat small, frequent meals instead of two or three bigger meals a day to shed extra pounds, but eating this way does not boost metabolism and may increase diabetes and cardiovascular disease risk, researchers found.

In two groups of women fed five high-fat meals one day and two high-fat meals on a separate day, meal frequency did not affect 24-hour energy expenditure in either the obese group (2124 Kcal/day with five meals versus 2142 Kcal/day with two meals) or the lean group (1724 versus 1683 Kcal/day, respectively), according to , of the University of Warwick in Coventry, England, and colleagues.

The researchers presented their findings Wednesday at the in Liverpool, England.

The work expands on a previousin the journal Diabetes Care, in which University of Warwick researchers showed that eating a single high-fat meal increased low-level inflammation in the body by releasing gut-derived endotoxin bacteria into the blood.

This type of inflammation has been linked to an increased risk for metabolic disorders, Piya told 番茄社区.

In the new study, Piya and colleagues examined whether small, frequent meals would increase the release of the gut-derived bacteria into the blood of obese and lean subjects, and whether energy expenditure was influenced by meal frequency when daily calorie intake remained the same.

The crossover study included 24 lean (mean age 34 years, mean BMI 22.9 kg/m²⁾ and obese (mean age 42 years, mean BMI 36 kg/m²) women who ate two or five high-fat (50% fat) meals on 2 separate days, with the same total number of daily calories eaten each day.

On both days, energy expenditure was measured over the course of the day and night in whole-body room calorimeters, and blood samples were taken every 2 hours from 9 a.m. to 9 p.m. Serum endotoxin, glucose, insulin and lipids also were measured.

"The women lived in the room for 24 hours, so we do feel very confident that we got an accurate picture of their energy expenditure," Piya said.

There was also very little difference in satiety associated with meal frequency in the lean and obese women, according to Piya.

"The obese women reported being slightly more hungry on the two-meal diet, but the difference was small," he said. "The main finding was that 24-hour energy expenditure, if measured properly, doesn't really change no matter how many times you eat, as long as total calories and the type of food are the same."

Among the other study findings:

• The obese women had increased area under the curve (AUC) for insulin, glucose, homeostatic model assessment insulin resistance (HOMA-IR), and triglycerides with decreased HDL (P<0.01), compared with the lean women, for both meal visits.
• For the entire group, fasting endotoxin correlated with triglyceride level (r=0.32, P<0.05), and AUC for endotoxin and triglyceride level correlated in the five-meal day (r=0.44, P<0.05) but not the two-meal day.

• At bedtime, endotoxin levels were significantly higher during the five-meal day compared with the two-meal day, especially among the obese women.

Small, frequent meals are often recommended for diabetics to minimize glucose spikes, but Piya said metabolically healthy obese people may benefit from eating less frequently.

"Some people like to eat a couple of times a day, and our research suggests that this may be a good way to lower inflammation and metabolic disease risk," he said.

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