Background: Methylenetetrahydrofolate reductase (MTHFR) is an enzyme responsible for producing an active form of folate. The MTHFR T677T genotype may have adverse health effects associated with weight gain and a reduction in folate availability. Aim: In this study, we examined the influence of the MTHFR C677T variant on BMI and determined its role as a risk factor for obesity. We also assessed the relationships between the MTHFR C677T genotype and folate and vitamin B12 concentrations in subjects before and after radical weight loss. Methods: The study group consisted of 1712 Caucasian adults of Polish nationality with a wide range of body mass indexes (BMIs). DNA was extracted from the blood, and the C677T variant was tested with RFLP-PCR and real-time-PCR. Results: There was no significant influence found for the MTHFR 677 TT genotype on BMI or the obesity risk in codominant, dominant or recessive inheritance models. Individuals with obesity and the TT genotype had significantly lower folate concentrations. After radical weight reduction, the impact of the risk genotype, as well as homeostasis between folate and vitamin B12 in TT homozygotes, seems to be attenuated. Conclusion: Although the MTHFR 677TT genotype is not directly related to a higher BMI in Polish adults, it has a detrimental effect on folate concentrations in individuals with high BMI values.

AbstractIntroductionObesity is currently one of the world's most serious health problems and the number of obese people is constantly increasing. Unhealthy food habits, especially snacking and eating at night, result in increased energy intake and subsequently lead to weight gain. The aim of the study was to assess the frequency of snacking and night-time eating among obese patients.Materials and MethodsThe study involved 476 obese people. For all subjects, anthropometric measurements (body weight and height) were taken and the body mass index (BMI) was calculated. Blood tests were also performed, including total cholesterol and fasting glucose levels. Data concerning the age and detailed clinical history of each patient were collected from the medical records. Survey questionnaires were used to assess eating habits, including the prevalence of snacking and night-time eating.ResultsThe patients’ average age was 42.9 ± 11.9 and the BMI was in the range of 32.3–58.8. The majority of the participants (63%) had a BMI above 40 kg/m2, 26% of them had a BMI in the range of 35–39.9 kg/m2, and 11% of the subjects had class I obesity (BMI: 30.0–34.9 kg/m2). In the study group, 32% of the patients had type 2 diabetes, while 12% had pre-diabetes. In addition, 42% of the patients exhibited total cholesterol levels above 190 mg/dl and in the case of 52% of the patients, LDL cholesterol levels exceeded 115 mg/dl. The habit of snacking was characteristic for 89% of the respondents and 50% admitted to eating at night. Sweet foods were indicated as a snack of choice by 57% of the survey participants. A positive association between snacking and eating at night was also observed (OR = 11.55, 95% CI: 4.51–29.6 p < 0.0001).Conclusions/DiscussionThe study has demonstrated that snacking is very common among the surveyed obesity patients. What is more, it is often accompanied by night-time eating. The obtained results show how important it is to focus on actions aimed at helping the patients change their eating habits.