Scientists studied more than 4,000 British primary schoolchildren aged nine and 10 who answered questions about what they ate for breakfast, and how often.
More than a quarter did not having breakfast every day. These children were much more likely to have blood markers associated with diabetes risk than those who always ate breakfast.
They had higher insulin levels after not eating, and they were more insulin resistant -- their bodies were less able to respond to the hormone.
Their blood sugar levels were also very slightly higher than those of breakfasting children.