During the COVID-19 pandemic, most countries took precautionary steps to save their citizens by initiating a lockdown and stopping all social activities by closing schools, companies, entertainment places, markets, gardens, and other social gathering places. As children stayed at home with no physical activities, their weight may have increased. The purpose of this study was to examine the link between fast food, sugars, or soft drinks and the ongoing domestic lockdown of the COVID-19 pandemic. This phenomenon was studied in three different cities from three different countries (Saudi Arabia, Britain, and Turkey) from the perspective of children’s parents. The study sought to address three research questions regarding children’s well-being during the COVID-19 lockdown period. First, was children’s nutrition affected during this period? Second, did children's weight increase? Third, were there any statistically significant differences in children’s dietary patterns based on their gender and nationality? A questionnaire was administered to 330 parents of children aged four to seven years in the three targeted countries. The study found that most parents cared about their children's nutrition and prepared food at home (96.1%) during the lockdown. Sixty-three percent of parents indicated that children did not gain weight. Additionally, differences in children’s nutritional systems were found between Saudi and Turkish children; the nutritional system of the Turkish children was better than that of Saudi children during the lockdown. Additionally, there were statistically significant differences in children’s nutrition due to gender, with better nutrition for boys than for girls.