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The International Agency for Research on Cancer (IARC) classifies night shift work as Group 2A (probably carcinogenic; the grade describes how certain the evidence is, not how large the risk is). For the heart, Vetter 2016 found in two large cohorts of US women nurses that more years of rotating night shifts went with a higher risk of coronary heart disease, though the absolute increase was small and the study was observational. Circadian misalignment may add risk through sympathetic arousal, inflammation and metabolic disturbance.
The core problem with shift work is not less sleep but an internal clock out of step with the light and dark outside: the body's master clock (the suprachiasmatic nucleus) is set by light, and melatonin is the darkness signal it sends. The International Agency for Research on Cancer (IARC) classifies night shift work as Group 2A, probably carcinogenic; the grade describes how certain the evidence is, not how large the harm is.
The effect of time-restricted eating may depend on where the eating window falls in the body clock. In one small crossover trial of men with prediabetes, a 6-hour early window with dinner before 3 p.m. improved insulin sensitivity and blood pressure even with weight held steady. Shift work pulls eating out of step with the light-dark cycle, so results like these do not carry over.
The hypothalamic-pituitary-ovarian axis that controls the menstrual cycle is tied to the body clock, so crossing time zones and shift work can disrupt the cycle. This belongs in the same family of causes as stress, eating too little energy and rapid weight change: all of them tell the hypothalamus that now is not a good time.
Caffeine does more than keep you awake; it can also delay the body clock. So for shift workers, when you drink it matters more than how much: keep coffee to the first half of the shift so it does not push an already misaligned clock even further.