Meal-frequency effects on plasma hormone concentrations and cholesterol synthesis in humans

Abstract

To examine meal-frequency effects on circulating hormone concentrations and cholesterol synthesis, male subjects consumed liquid diets given as either six evenly spaced (ES) or three diurnal (DI) meals over 3 d. Deuterium oxide was given on day 2 and blood sampled every 4 h over days 2 and 3 to measure plasma cholesterol, glucose, insulin, and glucose-dependent insulinotropic polypeptide (GIP) concentrations and cholesterol synthesis. Cholesterol synthesis was determined from deuterium incorporation into plasma free cholesterol by using constrained and unconstrained curve-fit models. Plasma total cholesterol concentrations decreased in both ES and DI groups (P < 0.05). The ES group had lower insulin (P < 0.05) and GIP (P < 0.001) concentrations compared with the DI group. Cholesterol synthesis was reduced (P < 0.01) in the ES vs the DI group when determined by using constrained (0.050 +/- 0.002 vs 0.075 +/- 0.005 pools/d, respectively) and unconstrained (0.072 +/- 0.005 vs 0.119 +/- 0.011 pools/d, respectively) models. These data suggest meal frequency-dependent control of cholesterogenesis via hormonally mediated mechanisms.

Glycemic index in chronic disease: a review

“…However, it has been shown that neither fat nor protein in the amounts found in most foods (with the exception of peanuts and most nuts) Lower postprandial glucose rise (Jenkins et al, 1990(Jenkins et al, ,1992Bertelsen et al, 1993;Jones et al, 1993) Reduced daily mean insulin levels (Jenkins et al, 1990(Jenkins et al, ,1992Bertelsen et al, 1993;Jones et al, 1993) Flatter gastric inhibitory polypeptide response (Jenkins et al, 1990(Jenkins et al, ,1992Bertelsen et al, 1993) Decreased 24 h urinary C-peptide output (Jenkins et al, 1989(Jenkins et al, ,1992 Prolonged suppression of plasma free fatty acids (Jenkins et al, 1990) Reduced urinary catecholamine output (Jenkins et al, 1990) Lower total and LDL cholesterol levels (Jenkins et al, 1989Arnold et al, 1993;Cohn 1964) Reduced hepatic cholesterol synthesis (Jones et al, 1993) Decreased serum apolipoprotein B levels (Jenkins et al, 1989) Decreased serum uric acid levels Raised urinary uric acid excretion Adapted from Jenkins et al (1995). Glycemic index in chronic disease LS Augustin et al significantly alters the glycemic response (Wolever et al, 1994).…”

“…Increasing meal frequency in isocaloric diets in diabetic and non-diabetic subjects has been shown to reduce postprandial glucose rise (Jenkins et al, 1992, Bertelsen et al, 1993Jones et al, 1993), daily insulin levels (Jenkins et al, 1992;Bertelsen et al, 1993;Jones et al, 1993) and 24 h urinary C-peptide output (Jenkins et al, 1989(Jenkins et al, ,1992. Increasing meal frequency is now included in the recommendations given for the management of diabetes by the American Diabetes Association (1994).…”

“…The 'nibbling' vs 'gorging' paradigm has shown that increasing meal frequency (from 3 to > 9 meal=day) reduced total and LDL cholesterol, apolipoprotein-B and serum uric acid levels in healthy subjects, after a period of 2 weeks (Arnold et al, 1993;Jenkins et al, 1989Jones et al, 1993). Significant lipid reductions in total and LDL cholesterol (0.23, 0.16 mmol=l, respectively) were also reported in the Rancho Bernardo trial on more than 2000 men and women aged 50 -89 y, when meal frequency was increased from 1 -2 meals per day to 4 meals per day (Edelstein et al, 1992).…”

Sleep, circadian rhythm and body weight: parallel developments

“…The reduced diet-induced thermogenesis with the irregular meal frequency may lead to weight gain in the long term (102) . With a regular meal frequency glucose excursions are blunted, net insulin production is reduced, and LDLcholesterol concentrations tend to be lowered, mainly due to gastric emptying slowing down, and insulin production being reduced (103)(104)(105)(106)(107)(108)(109)(110)(111) . The net result is that lipid oxidation is favoured at the expense of glucose oxidation and lipid storage, and cholesterol synthesis is reduced.…”

“…This may reduce adiposity and the level of circulating fatty acids, thereby leading to systematic, adaptive changes in both lipid and carbohydrate metabolism. Also examples of long-term responses to a sustained regular meal frequency such as improved glucose tolerance, and moderately reduced fasting plasma total and LDL-cholesterol, and a higher HDL:LDL cholesterol ratio are observed in normolipidaemic free-living subjects, as well as in type-II diabetes patients (103)(104)(105)(106)(107)(108)(109)(110)(111) . Also for cholesterol synthesis, meal frequency-dependent control of cholesterogenesis appeared to be mediated via hormonal mechanisms (97) .…”