This is quite a common theme regarding "hypos" for type 2's on diet only /metformin. There is a lot of confusion caused by the definition of a "Hypo"
"Hypo" is short for hypoglycaemia, which simply means low blood sugar. However, there is a massive difference between low blood sugar and the sort of hypo often referred to in relation to diabetes. Perhaps I can give my understanding.
Low blood sugar is not caused by diabetes. ANYONE, diabetic or non-diabetic, can get low blood sugar. Where energy demands are greater than the energy provided by the food (or drink) we've consumed, our blood sugar will continue to fall as demand is greater than supply. I've recorded 3.1 and I've known of people hitting the 2's (my athletic non-diabetic daughter - tested her once when she had an episode) This can lead to light-headedness or dizzy, feeling emotional, etc. Eventually, the liver will release Glycogen to compensate and bring BGs back up. The ONLY reason why a diabetic on diet only/metformin may be more likely to get this than a non-diabetic is because we are more likely to be on a diet and fall into the energy out being greater than the fuel in trap.
When referring to diabetic hypos, we are normally referring to the sort of dangerous hypo that can occur with an insulin dependant diabetic, or one on strong sugar-lowering drugs (not metformin) Here, BGs can fall into the 1's and the individual could become comatose and, ultimately, die. Intervention by a third party to help is sometimes required. An aware Insulin dependant diabetic will solve the problem themself by taking on board some instant fuel (such as with glucose tablets) to raise BGs. This problem is caused by the intake of insulin being greater than that needed. Perhaps the individual miscalculated the dose needed, or didn't eat the expected food on schedule, or experienced greater exerciser than planned, or drank sugar lowering alcohol in quantities without adjustment. Whatever the cause, the insulin taken has dropped BGs greater than the expected need. This is why Metformin doesn't cause Hypos. It doesn't stimulate the release of insulin as some drugs do. It merely makes the liver release slightly less sugar after food than it normally would, and makes the insulin we DO produce (which occurs after food when our BG is rising) more effective. So it can stop our sugar level from rising quite as high as it would after food, but it doesn't LOWER it as insulin does.
So, in summary, diabetes doesn't cause hypos. Metformin doesn't cause hypos. Insulin can. Insulin-stimulating drugs can. Lack of food causes low blood sugar for either a diabetic or non diabetic (officially a hypo, but not dangerous and not requiring outside assistance). There is a big difference between low blood sugar and a dangerous hypo. This is why your GP says you can't get hypos - he's referring to dangerous insulin-generated hypos, and he's right. But you can (and obviously do) get low blood sugar.
What you are experiencing is almost certainly low blood sugar.
This shouldn't stop you losing weight though. Have a look on the low carb diet forum. There are lots of ways of keeping your energy levels up without increasing your carbohydrate intake, and without the need for sugary drinks (these just crank your BGs too high and make you feel bad again when they come back down to healthy levels - remember, non diabetics spend nearly all their time in the 4's, and frequently in the threes) Perhaps your diet reduces your carbs without raising the healthy fats enough to compensate. So again, i'd say have a look at the low carb thread and get some ideas.
Hope this helps.
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