We can control type 2 diabetes by following a diet that is low in fat, low in sugar, low in salt, and high in fiber. It should consist mainly of plants and other foods with low glycemic index numbers, and be washed down with lots of water.

There are times however, no matter how successful we are at controlling our diabetes, that we experience 'unexplainable' swings (up or down) in our blood glucose levels.

The reason is simple: we all have slightly different reactions to various foods, ie some foods will increase (or decrease) blood glucose levels for some people while others will experience no effects, adverse or otherwise, from eating these foods.

To become adept at controlling our diabetes we need to know how we are affected by particular foodstuffs and drinks. We can only find this out by keeping track of our responses to them.

To help, here are some notes on various foodstuffs and drinks that may affect your blood glucose levels in various ways. You should check these tips for controlling blood sugar against your own experience of how particular foods affect you.

Coffee

Your blood sugar may rise after you drink coffee, even sugarless black coffee, due to the caffeine it contains.

The caffeine in black and green tea or other drinks can have a similar effect on your blood glucose.

Strangely, there are other compounds in coffee that have beneficial effects on your health. These include antioxidants such as chlorogenic acids and melanoidins, as well as N-methylpyridinium, which can boost cell defense mechanisms.

So how does coffee, green tea etc affect your blood sugar levels?

Refined bread

The refined flour in white bread gives it a high value on the glycemic index, in excess of 70. Since it is digested quickly and produces a rapid high spike in the level of your blood glucose.

So you should eat bread made from 100% wholemeal flour.

Bagels are often touted as a healthy alternative to white bread. Not so, if you are diabetic. Bagels contain more carbs and calories than a slice of bread … even the wholemeal ones.

What is the best bread for you?

Sugar-free foods

These seem like a safe bet when you are diabetic. But this is not always true.

Many sugar-free foods contain oodles of fat added to impartial flavor. If you are a type 2 diabetic you need to rid your diet of fat as far as possible in order to unblock the glucose receptors in your muscle cells.

Sugar-free foods may also contain a lot of starch, the main form of carbohydrates. You can only find out by checking the labels.

Sugar alcohols, such as sorbitol and xylitol, are often added to sugar-free foodstuffs to make them taste sweet. While these compounds have fewer carbs than sucrose (table sugar), they may still have enough to boost your blood glucose levels. Again, check the labels.

Eating out

Going to restaurants always presents problems for diabetics. Trying to decide whether a dish on a menu meets your low-fat, low-sugar diet criteria can be difficult.

Food based on Chinese, Japanese and other Eastern cuisines is, in the main, quite healthy.

However the white rice served in these restaurants contains lots of carbohydrates. It also has a reliably high GI value which means that the carbs are digested quickly and then can give rise to a rapid spike in blood glucose levels.

Some Eastern foods also have a high fat content. You need to avoid these foods.

You need to be cautious when eating out in other Western restaurants. Pizza, French fries and other foods contain lots of carbs and fat.

No matter where you eat, you should note the foods you have ateen. You should then check your blood sugar about 2 hours later. After a while a pattern will emerge and you'll be able to see which foods have an adverse effect on your glucose levels and what foods are safe to eat on a night out.

Colds and flues

Your blood glucose levels will rise when your body is trying to fight off an illness. There's not a lot you can do about that except to make sure you stay hydrated by drinking lots of water.

Note that some medicines can increase your blood sugar levels even further. These include some antibiotics and decongestants for clearing your sinuses. For example, decongestants containing pseudoephedrine or phenylephrine are known to raise blood sugar.

Cold medicines also sometimes have a little sugar or alcohol in them, so look for products that do not contain these ingredients. Antihistamines, however, do not cause a problem with blood glucose.

You should ask your pharmacist about the possible effects of over-the-counter meds before you buy them. You should, of course, attend your doctor if an illness persists for more than two days or so.

Other medicines

Several medicines in common use can have an adverse affect on blood sugar levels.

Corticosteroids , such as prednisone, are used to treat rashes, arthritis, asthma, and many other conditions. They are known to boost your blood glucose levels.

Diuretics (or water pills) that help regulate high blood pressure can also affect blood sugar levels adversely.

Antidepressants can go either way … some raise, others tend to lower blood glucose.

Birth control pills containing estrogen can affect the way a woman's body handles insulin. Birth control injections and implants are known to raise blood sugar levels. However oral contraceptives are considered safe for women with diabetes. A combination pill containing norgestimate and synthetic oestrogen is recommended, although your doctor's advice should always be thought.

Female hormones

When a woman's hormones change during her menstruation menstruation, her blood sugar levels change also. During menopause, the hormonal changes can make blood glucose even harder to control.

You should keep a monthly record of your blood glucose levels to get a better idea of ​​how they are affected by your menstrual cycle.

Stress

When you are stressed your body releases hormones, such as cortisol, that raise your blood glucose levels … no matter what the source (work, domestic, financial etc) of that stress.

Blood sugar increases due to stress are more common people with type 2 diabetes than more healthy persons.

You need to change the things that are stressing you if that is possible.

If not, you should train yourself to relax using deep breathing and physical exercise.

Dried fruit

Fresh fruit is always a healthy choice for a snack.

Dried fruit is just as healthy. However, as the water has been taken out, it will contain about average about three times the amount of natural sugars and carbs by volume as fresh fruit.

For example, one tablespoon of raisins, dried cranberries or dried cherries will have the same amount of carbs as three tablespoons of these fruits.

So you should only eat a third of what you would eat if the fruit were fresh.

Probiotics

Probiotics are foods such as fresh yoghurt that contain healthy bacteria. These can improve your digestion. They may also help you control your blood glucose levels.

But be cautious. Some yogurts contain added sugar and fruit. You need to check the labels and note the amount of carbohydrates. Your best bet is plain or light yogurt without added sugar.

Vegan diet

Several studies have found that people with type 2 diabetes who switch to a vegan (all vegetable-based) diet have better blood glucose control. Most are able to reduce or give up their medications. A few have actually reversed their diabetes.

It can be difficult at first but if you follow a pure vegan diet you are guaranteed to experience very positive effects on your diabetes.

Cinnamon

Cinnamon is definitely one drug that helps reduce blood glucose levels two hours after a meal. It is also a handy way to add flavor to dishes without adding salt, carbs or calories.

In this writer's experience a sprinkling of this spice on his oatmeal in the morning is worth between 0.3 and 0.5mml / L (5.4 to 9mg / L). This is a significant drop (almost 7% on average) when your are aiming for a target of 6mml / L (108mg / L) two hours after breakfast.

Exercise

Physical activity will boost your overall health. It will also contribute to keeping your blood glucose levels under control.

However, as a diabetic, you need to tailor your exercise to suit your needs. If you work out hard enough to sweat and raise your heartbeat, your blood sugar may increase quickly and then drop.

In fact, intense or endurance-type exercise can reduce you blood glucose to a dangerously low level and keep it down for 24 hours or more afterwards. A snack before you started could help prevent it dropping too low.

You should check your blood sugar before, during, and after you exercise.

That said, moderate exercise can have a very positive effect on blood glucose levels. For example, cleaning the house or mowing the lawn can help lower your blood sugar.

There are many ways in which you can boost the amount of exercise you do. For example, walk up stairs instead of taking the elevator or park on the far side of the parking lot near your office or at your local supermarket. Small bits of moderate exercise all add up.

Sports drinks

The fact of the matter is that all you need after a workout is plain old H2O. Indeed unless you have had an extreme workout, plain water will replenish your fluoids perfectly.

Sports drinks are usually full of sugars, calories and carbs, so if you must imbibe one, read the label carefully. Some of them contain as much sugar as a soda drink.

Alcohol

Alcohol, the world's most beloved recreational drug, is low in nutrients but high in empty calories, ie calories that have little or no nutritional value.

Alcoholic drinks contain plenty of carbohydrates so drinking moderate amounts of alcohol will cause your blood sugar to go up. This initial rise soon wears off and the level of glucose in your blood starts falling.

If you continue drinking then your blood glucose can continue to fall until you end up with hypoglycaemia (dangerously low blood sugar levels, aka a hypo). Even if you do not experience a hypo, your glucose level can stay too low for up to 12 hours after drinking.

It's best to take your booze with food and to check your blood sugar two hours afterwards.

Heat

Heat makes your blood sugar harder to control.

You are better off inside with the AC on when it's hot outdoors. You should drink plenty of water to avoid dehydration, and test your glucose levels from time to time.

High temperatures can also affect your medications, glucose meter and test strips, so do not leave them locked in a hot car.