Click to read Can Type 2 Diabetes be Reversed
Click to read Very Low Calorie Diets & Type 2 Diabetes Reversal Part 1: Blood Glucose
I’d also recommend opening Table 1 and Table 2 from last week's post, as I’m not going to repeat those study details (1-21).
Now that you’re up to be speed with what happens to fasting glucose, HbA1c, and body weight with very low calorie diets, let’s look under the hood and see what's going on in terms of insulin resistance.
What happens to insulin and insulin resistance on very low calorie diets?
Type 2 diabetes is defined by two key problems:
- the body, presumably your body if you’re reading this, is resistant to the signals from insulin (watch the videos here to learn more about this); and
- the pancreas has lost some or even much of it’s capacity to produce insulin.
Early in the progression of type 2 diabetes, problem one is more prominent. The body responds by keeping insulin high. When the pancreas becomes impaired, insulin therapy is the treatment of choice in most guidelines. So as you look at the fasting insulin results in Table 3, keep that in mind.
What you might see from the table is that fasting insulin is really all over the place. Partly this is because some people were on insulin therapy, and others weren’t. For the most part, very low calorie diets led to clear and substantial reduction in fasting insulin.
In the last post we saw that very low calorie diets reduced fasting blood glucose. What these two results tell us, is that after a very low calorie diet, the bodies’ of people with type 2 diabetes need less insulin to control their blood glucose.
Two things in our diet can have a big effect on insulin – carbohydrates and proteins (22-26). Given that both are likely to be lower in a very low calorie diet than someone’s normal diet, seeing lower insulin may come as no surprise, but remember these are fasting values, the volunteers hadn’t eaten for 10-12 hours before the blood samples were taken.
Fasting insulin isn’t a great measure by itself because it doesn’t tell us much about what’s going on. What we want is some indicator that looks at the both the amount of insulin and how well that insulin is doing its job. There some very involved procedures that can tell us in detail what’s happening where, but let’s start with the simpler options more commonly used.
A common way to gauge insulin resistance is called the Homeostasis Model Assessment or simply HOMA. This takes into account both blood glucose and blood insulin. There are newer and older versions (27). The newer version – HOMA2 – is more accurate, so I’ve calculated that where possible.
You can see the change in HOMA2 following very low calorie diets by clicking Table 4. You’ll see there are three results when calculating HOMA2:
- HOMA2-IR, which refers to insulin resistance. The bigger the number the worse the resistance.
- HOMA2-%B, which reflects how well the β-cells of the pancreas (the cells that make, store, and release insulin) are working. A higher number is better.
- HOMA2-%S, which tells us how insulin sensitive a person is. The higher the number, the better.
Despite HOMA2 not being the best method for assessing these things and some uncertainties about the use of medication in different studies, the picture that the results draw is one of reduced insulin resistance/improved insulin sensitivity, and improved β-cell function.
So to recap what we now know – very low calorie diets reduce fasting blood glucose and insulin resistance, and improve how well the pancreas functions. That’s exactly what we want when trying to reverse type 2 diabetes.
Next week we stay with the very low calorie diets by looking at what better more direct methods tell us is happening with the liver and pancreas. The liver is as central to glucose regulation as the pancreas, and plays a big role in type 2 diabetes, so stay tuned.
Click here to read part 3.
References: click here for a full list of references.
To learn more about type 2 diabetes and what you can do to better manage, and often reverse it, watch my free video education series. If you want one-on-one help dealing with your type 2 diabetes, contact me here to book a consultation.