Plasma leptin is influenced by diet composition and exercise

Abstract

OBJECTIVE: A low-fat, high-carbohydrate diet (r30% of total energy intake as fat) in conjunction with moderate intensity physical activity is widely recommended for weight maintenance and reduction. The aim of this study was to assess the effect of adding daily exercise to a short-term high-carbohydrate diet on fasting and postprandial leptin levels. SUBJECTS: Eight healthy, postmenopausal women aged 6074 y (mean7s.d.) (body mass index, BMI: 26.472.3 kg m À2 ; predicted maximal oxygen uptake: 2972 ml kg À1 min À1 ). DESIGN: Plasma responses were studied after subjects consumed the same high-fat, mixed meal on three occasions: after 3 days on a low-carbohydrate diet (35, 50 and 15% energy from carbohydrate, fat and protein, respectively) (Low-CHO); after 3 days on an isoenergetic high-carbohydrate diet (corresponding values 70, 15 and 15%) (High-CHO); and after 3 days on the same high-carbohydrate diet with 60 min of brisk walking daily (High-CHO-Ex). MEASUREMENTS: Fasting and postprandial plasma or serum concentrations of leptin, glucose and insulin. RESULTS: Fasting leptin was significantly higher (Po0.05) after the High-CHO (18.472.6 ng ml À1 ) (mean7s.e.m.) than after both the Low-CHO and the High-CHO-Ex interventions, which did not differ significantly from each other (16.972.1 and 15.572.0 ng ml À1 , respectively; P ¼ 0.08). Overall (fasted and postprandial states), plasma leptin concentrations were significantly higher after the High-CHO than after the High-CHO-Ex intervention. There was a strong, positive, linear relation between postprandial insulin responses and postprandial leptin concentrations at 6 h. In addition, there was a strong, negative, linear relation between whole-body insulin sensitivity (based on postprandial responses of glucose and insulin) and postprandial leptin concentrations at 6 h. CONCLUSION: Daily moderate intensity exercise, without concomitant changes in body fat mass, suppressed fasting and postprandial circulating leptin concentrations after consumption of a short-term high-carbohydrate diet. As shown in previous studies, insulin appears to be an important modulator of leptinaemia.

Effect of high-fat meals and fatty acid saturation on postprandial levels of the hormones ghrelin and leptin in healthy men

“…There is little or no correlation between the two hormones in several postprandial studies (Dagogo-Jack et al, 1996;Sinha et al, 1996;Pratley et al, 1997;Guerci et al, 2000;Herrmann et al, 2001;Poretsky et al, 2001) and this has lead to a revived interest in the influence of other dietary nutrients, including lipids, which have a blunted effect on insulin compared to CHO. Other trials which have shown a decrease in leptin after a fatty meal include lean (Romon et al, 1999) and obese subjects (Imbeault et al, 2001), and where HF test meals have followed high-and low-CHO acclimation (Koutsari et al, 2003). In a study of lean women given three HF (60 en%) or three high-CHO meals over 24 h, leptin continued to rise from an 0800 h nadir on both treatments but the postprandial response was less pronounced following the HF meals (Havel et al, 1999).…”

“…Our study of lean men showed a decrease in leptin but not ghrelin over 6 h following a HF meal, and an increase in saturation of the fatty meal did not further alter response of either hormone. Since meals rich in SFA reduce postprandial insulin sensitivity (Robertson et al, 2002), and insulin may be an important modulator of leptin (Havel et al, 1999;Evans et al, 2001;Koutsari et al, 2003;Romon et al, 2003;Fogteloo et al, 2004) and ghrelin (Mohlig et al, 2002;Saad et al, 2002;Flanagan et al, 2003), we wanted to determine whether increasing dietary SFA may differentially alter these hormones. Interpretation of the postprandial response of leptin is complicated by diurnal changes in hormone release, driven in part by meal time and/or composition (Schoeller et al, 1997;Fogteloo et al, 2004), with a decline postbreakfast followed by a midnight peak (Sinha et al, 1996;Coleman and Herrmann, 1999;Havel et al, 1999).…”

“…The postprandial response to HF feeding set against a diurnal change in circulating leptin is even more variable and circulating levels may increase (Dallongeville et al, 1998;Imbeault et al, 2001), decrease (Havel et al, 1999;Romon et al, 1999;Evans et al, 2001;Imbeault et al, 2001;Koutsari et al, 2003), or not change (Weigle et al, 1997;Guerci et al, 2000;Monteleone et al, 2003;Tentolouris et al, 2003) following a fatty meal. Changes in both hormones in response to dietary fat are commonly less pronounced than for CHO (Havel et al, 1999;Romon et al, 1999;Monteleone et al, 2003;Greenman et al, 2004) and it has been suggested that insulin may play a critical role in regulation (Evans et al, 2001;Mohlig et al, 2002;Saad et al, 2002;Flanagan et al, 2003;Koutsari et al, 2003;Fogteloo et al, 2004).…”

Serum leptin concentrations in relation to dietary patterns in Chinese men and women

“…Physical activity may have too remarkable an impact on serum leptin to be eliminated by adjustment in the model. It is generally the main way for a person's energy expenditure, which indirectly regulates leptin (3,28) . Interaction between age, current smoking status and the Western pattern was observed in our study.…”

Effects of a weight-reduction program with orlistat on serum leptin levels in obese women: A 12-week, randomized, placebo-controlled study

“…The degree of short-term caloric restriction has an effect on acute changes in serum leptin levels that may not be correlated with fat mass loss. 31,32 In the present study, the patients in both study groups were encouraged to consume a diet containing ∼1200 to 1600 kcal/d. However, during the study period, the control of the patients' diet was based on self-report.…”