Diagnosis of diabetes. Diagnostic tests?

Hello, My father never had diabetes. He got a full body check up and blood glucose levels were normal later after 10 days, he was feeling dizzy, so I asked him to take a glucose test and the result was 139 fasting and 232 post lunch, then we consultated a doctor (Neurologist, since my father is stroke patient) who advised diet control and Tab Zoryl M1 for ten days. After ten days we got him tested again and the result is 134 fasting and 223 post lunch. Ketones in urine test are negative. So my question is, does high glucose levels necessary means he has diabetes and if yes how did the doctor know it is type two diabetes, is it because of the ketone levels being zero? And 223levels is it a cause for concern. Should I ask him to take any other diagnostic tests? Please also advise on the measures to reduce the sugar levels to normal. He is 85kg & 5.7 feet, what should be his calorie intake and I'm keeping him completely on low GI food and white meat. Please find the reports in the attach.