Due to limited data about the impact of lockdown on health status, the present study aimed to investigate the impact of COVID-19-related lockdown on changes in dietary habits, physical activity and serum markers in healthy adults. A total of 38 asymptomatic adults aged from 23 to 59 with a normal BMI (22.5 kg/m²) participated in baseline and post-lockdown measurements that included dietary and physical activity assessment, anthropometric measurements and blood samples; and the lockdown survey which included dietary assessment and questionnaires about changes in lifestyle and physical activity. A decreased diet quality during lockdown was observed (Healthy Eating Index reduced from 64.59 to 61.08), which returned to near baseline post-lockdown. Energy intake decreased during lockdown (p = 0.002) and returned to baseline post-lockdown. Despite lower physical activity levels during lockdown (p = 0.035), we observed no significant changes in body composition. However, we observed a significant increase in serum glucose (p = 0.005), total cholesterol (p = 0.003), and low-density lipoprotein (LDL) (p = 0.049) post-lockdown. Increase in serum glucose levels was pronounced in subjects with higher increase in energy intake (p = 0.039), increased omega-6 fatty acids intake (p = 0.016), those who were exposed to several risky contacts (p = 0.018, compared to those with less risky contacts) and those who were not active in nature (p = 0.008, compared to those active in nature). Increased serum LDL was correlated to decreased monounsaturated fatty acids intake (p = 0.028). Within the limits of this preliminary report, changes in serum markers observed among healthy subjects point to a possible impact of COVID-19-related lockdown on adults’ health to be confirmed in larger groups.

Diets omitting whole food groups pose a risk for micronutrient insufficiencies, but there are no data as to whether those are suitably attenuated with dietary supplements (DS). Micronutrient intakes with food and DSs were analyzed in 130 healthy adults: 32 vegans, 37 vegetarians, 24 following low-carbohydrate high-fat diet (LCHF), and 37 omnivores. A total of 63% used DS (84% of vegans, 75% of LCHF, 54% of vegetarians, and 46% of omnivores); however, a DS did not always tackle dietary insufficiencies. Vitamin B₁₂ was often supplemented in vegans in doses substantially higher than recommended, but it was supplemented less often in vegetarians, despite the low prevalence of sufficient intake. Only 43% of participants supplemented vitamin D in wintertime, 23% of them with an insufficient dose. Supplementation of potassium, calcium, and iodine was rare, despite low intake adequacy with food alone in all groups. Some micronutrients were supplemented unnecessarily, such as vitamin K, riboflavin, biotin, and iron. Multimicronutrient DSs were used often; they increased intake adequacy of group B vitamins but failed to sufficiently supplement vitamin D, potassium, calcium, and iodine. Although DS use increased micronutrient intake sufficiency when used properly, the knowledge on micronutrient inadequacy in all dietary patterns should be increased and the public should be educated on the proper use of DSs. Multimicronutrient DSs should be reformulated to tackle the insufficiencies.

Age-related noncommunicable diseases are a major health burden in developed countries, with oxidative stress being a key contributing factor. This cross-sectional study aimed to test the hypothesis that redox status among 88 participants with a particular interest in nutrition and habitually following 4 popular dietary patterns (vegan, vegetarian, low-carbohydrate high-fat, and omnivorous), is similar, but correlates with diet quality. Dietary intake was assessed using food diaries, and venous blood samples were collected to measure serum total antioxidative capacity (TAC), bilirubin, nicotinamide adenine dinucleotide (NAD⁺)/reduced form of nicotinamide adenine dinucleotide (NADH) ratio, and sirtuin 1 concentration, and the expression of antioxidative enzymes in leukocytes. TAC and the NAD⁺/NADH ratio were higher in the vegan group compared with the vegetarian group, whereas bilirubin concentration was higher in the omnivorous compared with the low-carbohydrate high-fat group. Other differences between the dietary groups were not significant. NAD⁺/NADH ratio and sirtuin 1 were positively correlated with diet quality, assessed with the Healthy Eating Index. Correlation analysis between dietary variables and redox markers revealed only a few weak to moderate associations. However, a hierarchical regression model including age, gender, and dietary variables explained 19.8% of the variance in TAC, 21.2% of the variance in the NAD⁺/NADH ratio, and 44.3% of the variance in sirtuin 1 concentration. Therefore, in healthy, relatively young participants with appropriate energy intakes, endogenous mechanisms are able to compensate for oxidative stress to a similar extent, regardless of dietary pattern. Nonetheless, overall diet quality and food selection appear to play a meaningful role in redox balance.