A comparison of the effect of free access to reduced fat products or their full fat equivalents on food intake, body weight, blood lipids and fat-soluble antioxidants levels and haemostasis variables.

OBJECTIVES: To compare the effects of free access to reduced fat products or their full fat equivalents on fat and energy intake, body weight, plasma lipids and fat-soluble antioxidants concentrations and haemostasis variables. DESIGN: A multicentre open randomised controlled trial in which intervention and control groups were followed in parallel for six months. Volunteers had free access to 44 different foods either in reduced fat or full fat version, covering between 30 and 40% of energy intake. The remainder of energy intake was covered by foods bought in regular shops. SETTING: Zeist, Wageningen and Maastricht, The Netherlands. SUBJECTS: Two hundred and forty-one non-obese healthy volunteers who had no intention to lose weight. MAIN OUTCOME MEASURES: Food intake, body weight, plasma lipid, vitamin E, beta-carotene, lycopene and fibrinogen concentrations, plasma factor VII clotting activity, and plasminogen-activator-inhibitor-I antigen level. RESULTS: One hundred and three volunteers in the full fat group and 117 volunteers in the reduced fat group completed the study. Energy and fat intake from the free access products was lower in the reduced fat group, but no difference in energy and fat intake of other products occurred. Body weight, energy-, fat- and vitamin E intake and percentage of energy derived from fat decreased in the reduced fat group. No other statistical significant intervention effects were observed. Blood lipid concentrations, factor VII activity and plasminogen-inhibitor-activator-1 level were reduced after consumption of reduced fat products. CONCLUSIONS: When subjects without intention to lose weight limit fat intake by switching from ad libitum consumption of full fat products to reduced fat products body weight gain is prevented, and fat and energy intake are reduced. Such a switch may have beneficial effects on biochemical cardiovascular risk factors. We concluded that reduced fat products will help in a population strategy aimed at preventing overweight and obesity, they will also be effective in maintaining a lower body weight after slimming. Ad libitum consumption of reduced fat products will be ineffective for those individuals that want to reduce body weight because they are currently overweight or obese.

A long-term study on the effect of spontaneous consumption of reduced fat products as part of a normal diet on indicators of health.

The growing public concern with the adverse effects on health of a high fat intake has led to a proliferation on the market of reduced fat products. However, no consensus exists on the effectivity of reduced fat products to decrease energy intake. The studies that have investigated this topic have included small numbers of subjects, studied under laboratory conditions and over a relatively short period of time. Therefore, we have executed a long-term study in which volunteers had free access to both reduced fat, commercially available products in the laboratory as well as to products obtained from regular shops. We here report the feasibility of such a type of study and the effects of consumption of reduced fat products on blood levels of cholesterol, haemostasis variables, antioxidants and parameters of the immune system. The study was a multicentre parallel comparison trial of six months (so-called MSFAT-study). 241 volunteers received either reduced fat products or full-fat products and the products were clearly labelled as such. Two months before the start of the study, a 1 month adaptation period was executed to optimize the experimental procedures. Food intake was recorded before the start of the adaptation period and 2-4 weeks, 3 months and 6 months after the start of the study. Blood samples were taken before, after 2, 4 and 6 months of the study. In addition, a selection of the reduced fat and full-fat products was sensorically evaluated three times during the study by a subgroup of the volunteers. 220 volunteers completed the study. The reduced fat group consumed on average 46% less fat from the so-called MSFAT-products obtained from the shop at the laboratory than the control group and consumption of these MSFAT-products did not decrease in either of the groups during the time course of the study. The palatability of the reduced fat and full-fat products was similar and as expected, the perceived fattiness of the full-fat products was higher than that of the reduced fat products. No effects were found on blood levels of cholesterol, haemostasis variables, parameters of antioxidant status and immune system characteristics. In conclusion, the experimental manipulation of the fat content of the diet that was achieved and that remained stable throughout the 6 months of the study indicates that this type of set-up is feasible to assess the effects of long-term nutritional intervention in large groups of volunteers under semi-controlled conditions. The regular use of reduced fat products did not positively but also not adversely affect blood cholesterol levels, antioxidant status, haemostasis factors and the body's immune system.

Energy and fat compensation during long-term consumption of reduced fat products.

The objective of this study was to investigate the behavioral response to the long term realistic consumption of reduced fat products. During six months, a control group of 103 subjects had free access to about 45 commercially available full-fat products, and a reduced-fat group of 117 subjects had access to the reduced fat equivalents. These experimental products covered about 37% of total energy intake in the control group and 30% of energy intake in the reduced fat group. Other non-experimental food products were bought in regular shops. The results showed that, compared to a baseline measurement before the start of the study, energy intake increased from 10.4 MJ/day to 11.2 MJ/d in the control group, whereas it remained constant at 10.2 MJ/d in the reduced fat group. Fat intake in the control group increased from 99 g/d (35.6en%) to 123g/d (40.6en%), whereas fat intake in the reduced fat group decreased from 95 g/d (34.en%) to 90 g/d (32.7en%). The energy and fat intake from experimental products was lower in the reduced fat group (3.1 MJ/d, 37 g fat/d) than in the control group (4.2 MJ/d, 71 g fat/d). There was some compensatory response in the consumption of experimental products: the ingested amount of experimental products was about 10% higher in the reduced fat group (447 g/d) than in the control group (399 g/d)[t = 2.6; p < 0.01]. There was no compensatory response in the consumption of non-experimental products. Both the control and reduced fat group consumed about 7.1 MJ/d and 53 g fat/d from non-experimental products. It is concluded that long term consumption of reduced fat products leads to a lower energy and fat intake, compared to the consumption of full-fat products.