OBJECTIVE:To study the effects of 13 weeks conjugated linoleic acid (CLA) supplementation in overweight subjects after weight loss on weight regain, body composition, resting metabolic rate, substrate oxidation, and blood plasma parameters. DESIGN: This study had a double-blind, placebo-controlled randomized design. Subjects were first submitted to a very-lowcalorie diet (VLCD 2.1 MJ/d) for 3 weeks after which they started with the 13-week intervention period. They either received 1.8 g CLA or placebo per day (low dosage, LD) or 3.6 g CLA or placebo per day (high dosage, HD). SUBJECTS: A total of 26 men and 28 women (age 37.877.7 y; body mass index (BMI) 27.871.5 kg/m 2 ). MEASUREMENTS: Before VLCD (t ¼ À3), after VLCD but before CLA or placebo intervention (t ¼ 0) and after 13-week CLA or placebo intervention (t ¼ 13), body weight, body composition (hydrodensitometry and deuterium dilution), resting metabolic rate, substrate oxidation, physical activity, and blood plasma parameters (glucose, insulin, triacylglycerol, free fatty acids, glycerol and b-hydroxy butyrate) were measured. RESULTS: The VLCD significantly lowered body weight (6.971.7%), %body fat, fat mass, fat-free mass, resting metabolic rate, respiratory quotient and plasma glucose, insulin, and triacylglycerol concentrations, while free fatty acids, glycerol and b-hydroxy butyrate concentrations were increased. Multiple regression analysis showed that at the end of the 13-week intervention, CLA did not affect %body weight regain (CLA LD 47.9788.2%, CLA HD 27.4729.8%, Placebo LD 32.0742.8%, Placebo HD 22.5737.9%). The regain of fat-free mass was increased by CLA (LD 6.273.9, HD 4.672.4%) compared to placebo (LD 2.873.2%, HD 3.473.6%), independent of %body weight regain and physical activity. As a consequence of an increased regain of fat-free mass by CLA, resting metabolic rate was increased by CLA (LD 12.0711.4%, HD 13.7714.4%) compared to placebo (LD 9.1711.0%, HD 8.678.5%). Substrate oxidation and blood plasma parameters were not affected by CLA. CONCLUSION: In conclusion, the regain of fat-free mass was favorably, dose-independently affected by a 13-week consumption of 1.8 or 3.6 g CLA/day and consequently increased the resting metabolic rate. However, it did not result in improved body weight maintenance after weight loss.

Consumption of DGs in place of TGs does not alter EE but produces metabolic effects, particularly increases in fat oxidation, which may be associated with improved appetite control and energy balance.

Objective: To study the effects of 13 weeks conjugated linoleic acid (CLA) supplementation in overweight subjects on bodyweight maintenance, parameters of appetite and energy intake (EI) at breakfast after weight loss. Design: This study had a double-blind, placebo-controlled randomized design. Subjects: A total of 26 men and 28 women (age 37.877.7 y; body mass index 27.871.5 kg/m 2 ). Interventions: Subjects were first submitted to a very-low-calorie diet (VLCD; 2.1 MJ/day) for 3 weeks after which they started with the 13-week intervention period. They either received 1.8 g CLA or placebo per day or 3.6 g CLA or placebo per day. Additionally, subjects of the high dosage intervention replaced their habitual lunch by one meal of a protein-rich, low-energy supplement. EI was measured at breakfast and appetite profile after an overnight fast. Results: The mean body weight loss was 6.971.7% of their original body weight. Multiple regression analysis showed that at the end of the 13-week intervention, CLA did not have an effect on body weight regain. Feelings of fullness and satiety were increased and feelings of hunger were decreased after 13 weeks intervention by CLA compared to placebo, independent of %body weight regain. However, EI measured at breakfast was not affected by CLA. Conclusion: Appetite (hunger, satiety and fullness) was favorably, dose-independently affected by a 13-week consumption of 1.8 or 3.6 g CLA/day. This did not result in a lower EI at breakfast or an improved body-weight maintenance after weight loss.

Objective: To investigate the effect of 2 week use of oils high in linoleic (LA), g-linolenic (GLA) and oleic acid (OA) on energy intake (EI), macronutrient composition, parameters of appetite and taste perception. Design: A randomized placebo-controlled 2-week treatment, followed by a test day. Setting: Two-week treatments, daily life; test day, laboratory restaurant. Subjects: Eight overweight men and eight overweight women (body mass index 27.4 AE 1.5 kgam 2 ). Interventions: Three 2 week treatments, in which subjects replaced their habitual fat products by three different oils (relatively) high in LA (66.8%), GLA (20.2%) or OA (79.6%, placebo). The wash-out periods were 2 weeks. Before each intervention period, taste perception and sensory speci®c satiety was tested. Results: Even though energy intake was higher during dinner, subjects ate relatively less fat with LA (45.0 AE 9.4 E%, P`0.05) than with OA (48.3 AE 8.3 E%). Subjects did not distinguish the oils with the different fatty acids from each other. There was no relation between satiety or fat-speci®c satiety and taste characterization without as well as with sucrose. Although no differences were seen for the AUC of the appetite pro®le, at 15:00 h subjects were less satiated with LA (46.1AE 6.2 mm, P`0.05) or GLA (45.1 AE 5.8 mm, P`0.01) than after treatment OA (62.5AE 4.8 mm). 24 h EI on the test day was 7.6 ± 8.0 MJ and did not differ between treatments. Conclusions: Fat-speci®c satiety during dinner with LA vs OA was shown after a 2-week treatment of each oil, but no change in general satiety. Fat speci®c satiety was not related to taste perception or characterization of the oils.