大概是这样，没试对不对，你可以参考
flag <- matrix(c(unique(DATA$ID), NA), nrow = length(unique(DATA$ID)), ncol = 2)
for (id in unique(DATA$ID)) {
for (seq.G in 1:3) {
if (DATA[seq.G:(seq.G+3), "Gluoose"] > 10) flag[id,1:2] <- c(id, 1)
else flag[id,1:2] <- c(id, 0)
}
}

我也有个思路：
Flag <- df %>% group_by(ID) %>% slice(1) #这是为了把所有ID提取出来
Flagdf <- df %>% mutate(second=lead(Glucose)) %>% mutate(third=lead(second)) %>% na.omit() %>% filter(Glucose>=10,second>=10, third>=10) %>% mutate(flag_1 = 1) %>% merge(Flag, ., by="ID",all.x=T) %>% mutate(flag=ifelse(flag_1==1,1,0))

嗯嗯，万分感谢。

嗯嗯，谢谢。已解决！