The Consequences of Crash Diets

You know the feeling – you’ve been so tied up at work with meetings, phone calls, faxes and more meetings, that you didn’t have time for lunch or dinner. Your blood glucose has plummeted lower than a bug under your shoe and you’re craving food like a sumo wrestler on a grapefruit diet. When you finally get home, you gobble up everything in sight, restoring your blood glucose to levels that can at least contribute to minimal cognitive function.

So what’s the big deal? Well, having low blood glucose can actually be quite detrimental to your body, both in its obvious manifestations and in ways you may not be aware of. Not only can low blood glucose impair your mood and how well you process things mentally, but it may damage skeletal muscle fibers.

To determine organ damage due to hypoglycemia (low blood glucose), scientists injected varying levels of insulin into rabbits to create a low blood glucose level and to examine the effects of insulin and hypoglycemia duration on enzyme activity in the animals’ blood. Rabbits were divided into the following five treatment groups.

1. Low insulin dose (2U/kg) with hypoglycemia for 30 minutes.

2. Low insulin dose with hypoglycemia for 60 minutes.

3. High insulin dose (10U/kg) with hypoglycemia for 30 minutes.

4. High insulin dose with hypoglycemia for 60 minutes.

5. High insulin dose with 50% glucose and no hypoglycemia.

Blood glucose fell dramatically in all four hypoglycemic groups; no surprise there. But what’s intriguing is that serum creatine kinase (CK) levels increased dramatically after insulin injection in all the hypoglycemic animals, indicating that skeletal muscle damage occurred. On the other hand, the researchers observed no change in serum CK in the animals given glucose with the insulin injection. The added glucose kept the insulin from inducing a hypoglycemic state.

In addition, levels of the enzymes alanine aminotransferase, aspartate aminotransferasie and lactate dehydrogenase increased significantly in group 4 (high dose insulin for 60 minutes of hypoglycemia). Don’t let these monstrous words intimidate you. These enzymes are basic measures of liver or heart damage. For instance, if you damage the liver via drugs, injury, or in this case, insulin induced hypoglycemia, breaks or tears in the cell membranes of liver cells become large enough so that these enzymes leak out into the blood. This definitely isn’t something you want.

Bodybuilding, Dieting & Hypoglycemia

So what’s the moral of the story? First, because this study didn’t specifically address the effects of starvation or diet induced hypoglycemia, we can’t tell if the levels of hypoglycemia seen in these animals are similar to situations seen in humans. But keep in mind that bodybuilders on pre-contest diets often use a high protein, low carbohydrate, low fat approach. If you do this long enough, you will in essence induce a semi permanent hypoglycemic state.

Scientists who studied the effect of a pre contest dieting regimen in a male bodybuilder found this individual to be hypoglycemic. He also had elevated levels of serum CK. When this bodybuilder went from a pre-contest weight of about 167 pounds (76kg) to about 139 pounds (63kg), his percentage body fat dropped from 16% to less than 5%. Yet 25% of his weight was lean tissue – he lost 7 pounds of muscle and other lean tissue.

The questions I would pose are these. Can the loss of lean tissue be minimized via alterations in the diet, and is this loss of lean tissue related to a hypoglycemic state? Would adding just a few more carbs help a dieter retain lean tissue? Possibly.

For those of you who use insulin as an anabolic agent, I advise you to stop. Damaging your muscles from insulin induced hypoglycemia is the least of your problems. The purported benefits of injecting insulin definitely do not outweigh the risks. And we’re not just talking about low blood glucose. Injecting insulin is the quickest way to die.

So what’s the bottom line on managing or avoiding hypoglycemia? First of all, make sure you eat frequent small meals that contain a serving of lean protein, a serving of complex carbs and fibrous vegetables. This will ensure that you get a steady supply of glucose to fuel your brawn and your brain. If you’re looking to cut body fat to minimal levels, don’t drop your carb intake below 20% of your total calories. Not only will you be grouchy, but it won’t make your muscles happy either.