The influence of meal frequency on diurnal lipid, glucose and cortisol levels in normal subjects

Abstract

Diurnal levels of serum triglyceride, cholesterol, free fatty acids, glucose, and cortisol were measured in four normal persons on a fixed solid 65% carbohydrate diet under steady state conditions in a metabolic unit. Triglyceride levels in all subjects showed similar patterns, which unexpectedly did not bear a simple relation to meal frequency or distribution. With three equivalent meals per day at 09.00, 12.00 and 17.00 hours, 'fasting' triglyceride levels increased by about 0.3 g/l from a minimum value between 03.00 and 05.00 hours in the morning till before breakfast. After breakfast there was a continued rise till about 15.00 hours and then a overall fall in spite of the meal at 17.00 hours. Isocaloric change to eight equivalent meals, consumed between 09.00 and 23.00 hours, resulted in a similar although slightly more even triglyceride pattern. On eight equivalent meals, spaced evenly over the entire 24 h period, a different pattern was found with lower triglyceride values at daytime than at night. Increase in meal frequency did not result in a lowering of mean diurnal triglyceride levels. The cholesterol pattern followed the triglyceride pattern most clearly in subjects with high triglyceride levels. Glucose showed the expected postprandial increments. Cortisol rhythm did not change on varying meal frequency.

Diurnal Levels of Lipids, Glucose and Insulin in Type IV Hyperlipidemic Patients on High Carbohydrate and High Fat Diet: Comparison with Normals

“…After a carbohydrate-rich diet at home during a fortnight and for four consecutive six-day periods in the Metabolic Ward, mean fasting TG levels decreased in the last three periods by nearly 2 g/l (A2 compared to All. This differs from our findings in normals (29). This phenomenon, which is perhaps caused by adaptation to carbohydrate-rich food after an initial induction, has also been found by Antonis and Berson ( 2 ) and Lees and Fredrickson (12) in normals.…”

“…As the separation of chylomicrons and VLDL is based on flotation characteristics, it may well be that a proportion of the chylomicrons are big TG-rich particles of endogenous origin, which are known to appear on carbohydrate-rich food (15, 22). The finding that chylomicrons contributed mainly to the increase in serum TG in patients on both diets contrasts with findings in normals, in whom VLDL was the main contributor to the serum TG pattern (7,29). This could point to a defect in TG clearance in the patients, as big particles like chylomicrons are usually said to be preferentially hydrolysed by lipoprotein lipase when compared with smaller particles like VLDL (13).…”

“…Only a few reports dealing with hypertriglyceridemic patients have rendered an account of 24-hour patterns (24,25,26,27). We have recently reported diurnal levels of lipids, insulin and glucose in normals in steady state on carbohydrate-and fat-rich diets (7,29). This study has now been extended to type IV hypertriglyceridemic patients, who were investigated in the same manner as the normals.…”

Metabolic, endocrine and mood responses to nocturnal eating in men are affected by sources of dietary energy

“…In the study by Morgan et al, fasting NEFA concentration was higher in the evening than the morning [72]. However, the diurnal variations seen in the our and other studies when normal meals were provided throughout the 24-h period seem to be smaller (between 0.1 and 0.5 mmol NEFA/L) [72,110,117] than the 0.7 mmol NEFA/L above fasting levels needed to show a decreased insulin sensitivity [16].…”

Acute dietary effects on plasma lipids, lipoproteins and lipolytic enzymes in healthy normal males

“…There have been only few studies of diurnal lipid and Correspondence [13][14][15]. These have indicated that as with single fat meaIs the kind and the amount of both fat and carbohydrates acutely affect plasma lipids and lipoproteins.…”