Understanding Glucose: Ideal Blood Sugar Levels for Weight Loss 
Time to read 9 min
Time to read 9 min
Blood sugar levels are like a rollercoaster ride. If they rise too quickly or drop all of a sudden, you feel disoriented and dizzy.
And to add insult to injury, fluctuating glucose levels can keep you from losing extra weight.
Whether you're diabetic or completely healthy, understanding glucose can help you fast-track your weight loss journey.
There are ideal blood sugar levels for weight loss that can turn your body into a fat-burning machine.
Let's explore the science behind glucose and weight loss and how you can optimize your blood sugar levels to burn more fat.
Blood glucose, also known as blood sugar, is a type of simple sugar found in your bloodstream. It comes from various chemical reactions in our bodies and from the food we eat, especially carbs.
Blood sugar is an important energy source for the entire body, especially the brain and the muscles. So sugar isn't necessarily harmful.
However, we still have to watch our blood sugar levels because they can affect our overall health and how we gain or lose weight.
There's no one-size-fits-all when it comes to blood sugar levels. It depends on factors like your age, health status (diabetic, pregnant, healthy, etc.), and the time of day.
Generally speaking, there are three ideal blood glucose levels for a healthy adult:
Fasting Blood Sugar: Ideally 70 to 99 mg/dL and is measured after fasting for at least 8 hours (only allowed to drink water)
Preprandial Blood Glucose: Ideally 80 to 130 mg/dL and is measured before meals
Postprandial Blood Glucose: Ideally less than 180 mg/dL and is measured 2 hours after a meal (also called post-meal blood glucose)
When your blood sugar levels drop below 69 mg/dL, it's called hypoglycemia.
On the other hand, a high fasting blood sugar of 100-125 mg/dL could be a sign of prediabetes.
If your fasting glucose rises above 125 mg/dL, you might be diabetic and should consult a physician.
There are several ways you can measure blood glucose levels. Some can be done at home, while others are performed in a lab or with the help of a technician.
The most common tests include:
Hemoglobin A1c (HbA1c): Gives you a rough estimate of your average blood glucose levels over the past 2-3 months. It shows the amount of sugar stored in your red blood cells.
OGTT (Oral Glucose Tolerance Test): Done in a lab where you ingest a small amount of sugar and we observe how it affects your blood sugar levels
Fasting Blood Sugar: Measured after fasting for at least 8 hours
Postprandial Blood Glucose: Measured two hours after a meal
The first two tests are performed in a lab, while the other two can be done at home with a glucometer.
Now that you understand glucose and how your blood sugar works, let's take a look at how this impacts your weight loss efforts.
The ABCs of dieting tell you to in order to lose weight, you need to eat fewer calories. It's about being in a caloric deficit, which means burning more calories than you consume.
While this is theoretically correct, it doesn't take into account that your body is a complex structure full of hormonal and metabolic processes. A smarter approach is to count calories while keeping an eye on your metabolic health.
Your metabolic health is determined by five indicators: blood sugar levels, blood pressure, triglycerides, cholesterol, and waist circumference.
Your goal should be healthy weight loss by staying at an optimal blood sugar level. This will keep you metabolically healthy, less likely to develop chronic diseases, and you'll lose weight.
To do this, you need to understand how hormones, such as insulin, affect your blood sugar levels and, ultimately, your weight loss ability.
Insulin is one of the most important hormones in your body. Its primary role is moving blood sugar into your cells, mainly muscles and liver, to be burned for energy. You could say insulin is almost like a glucose burner.
Eating meals that contain carbohydrates stimulates insulin production in an attempt to control your blood glucose levels. Right after a meal, your insulin spikes, and the amount of insulin depends on your blood sugar levels.
Unhealthy eating habits, like eating too much sugar or processed foods, can make your body less sensitive to insulin because of your constantly high blood sugar levels.
This can eventually turn into insulin resistance, a sign of poor metabolic health where your cells no longer listen to insulin and refuse to let glucose in. Insulin resistance is often a precursor of diabetes if left untreated.
This is why controlling your blood glucose levels is so important in preventing insulin resistance and diabetes.
But how does this tie into your weight loss goals? Well, insulin promotes weight gain.
Unfortunately, insulin burns glucose to a limit. Generally speaking, insulin is an anabolic hormone, which means it favors weight gain and likes to build things up.
Insulin might be good at burning glucose, but once it becomes too much for your cells to take, it starts converting glucose into "stored glucose" or glycogen.
Once your liver and muscles can't take any more glycogen, insulin starts converting the excess glucose to stored fat instead. In other words, insulin only burns glucose as long as your blood sugar level isn't too high.
High insulin levels promote fat buildup and storage, which is something you don't want if you're trying to lose weight. Even worse, the high insulin levels signal your body not to burn fat cells for energy. It's almost as if insulin turns off fat burning.
This means we need to control our insulin levels if we want to burn fat instead of adding to our fat stores. Being a hormone that comes from your pancreas, it's hard to control your insulin release. You can, however, control what you eat.
Controlling your food intake helps control your glucose levels and, in turn, your insulin levels.
Since glucose levels play such a vital role in your weight loss or gain, it's important to control them. Your blood sugar needs to be at a certain level that promotes weight loss and keeps your body metabolically healthy.
The question is: what is that level?
The optimal blood sugar level for weight loss differs from one person to another.
There are several factors to take into consideration, including diet, physical activity, health status, and more.
However, a good rule of thumb is to stick to 70-85 mg/dL. This blood sugar level is optimal for burning fat and makes you less liable to insulin resistance, diabetes, heart disease, and an assortment of conditions.
Generally speaking, 70-100 mg/dL is the normal range for a healthy individual, but sticking to the lower limit of the range keeps your body in fat-burning mode.
Lower than 70 mg/dL, however, can be dangerous. Low blood sugar, or hypoglycemia, can have deleterious effects on your body, from irregular heartbeats to fainting and even hypoglycemic coma.
Plus, low blood glucose levels can make you uncontrollably hungry, which leads to unhealthy diet choices and subsequent weight gain. Lowering blood sugar levels might be beneficial to weight loss, but stick to the 70-85 mg/dL range. This will trigger your body to burn stored fat.
To monitor your blood glucose levels, you can do a blood sugar test with a glucometer a couple of hours after meals. This gives you an indication of how your body handles carbs, your insulin sensitivity, and whether you're in the optimal range for losing weight.
Another handy tool you can use is a CGM (continuous glucose monitor). A CGM is a small wearable device made for tracking glucose around the clock. It instantly tells you your blood sugar level at any time of the day, and some devices even alert you if it gets too high or too low.
While CGMs are typically prescribed to diabetics, non-diabetics can use them to monitor their glucose levels for weight loss.
You can see just how much your glucose rises with each meal and, therefore, estimate your insulin spikes.
Generally speaking, you don't want your blood sugar to rise by more than 30 points post-meal, especially if you're trying to lose weight. Using a CGM, you can see the changes before and after a meal and tweak your diet accordingly.
The continuous, real-time glucose data provided by CGMs can help you experiment with different foods and see how your body reacts.
Sometimes you think your diet is going well or a particular food is good for you, but in reality, it's messing up your sugar levels and keeping you from burning fat.
This is why diet control, as in choosing what you eat and not just reducing calories, is crucial for weight loss.
Now that you know the optimal blood sugar levels for weight loss and how to monitor them, how are you going to stay in that range? Your diet.
Dieting doesn't mean eating fewer calories to lose weight. It means choosing nutritious foods that have a low glycemic index.
The GI (glycemic index) is just a scale from 0 to 100, where food is ranked based on how quickly it raises your blood glucose. The lower the glycemic index, the smaller the glucose spike and the healthier the food is.
For example, eating an apple might not affect your blood sugar much because it has a glycemic index of 36. White bread, on the other hand, has a glycemic index of 75, which means it causes significant glucose spikes, pushing you out of the fat-burning range.
Sugary beverages and processed foods have extremely high GIs, leading to high blood sugar levels and too much insulin release. This is why people who regularly eat fast food are highly liable to developing obesity, insulin resistance, diabetes, and cardiovascular disease.
High-protein foods have a low GI and can help you remain in the fat-burning zone.
High-fat foods, surprisingly, also have a low GI and don't raise your blood glucose level much. This is why many people consider a ketogenic diet when they're trying to lose weight. In a ketogenic diet, you're essentially cutting out carbs and replacing them with fats and protein.
When your body isn't getting enough carbs, it starts looking for another source of energy. It hits your adipose tissue (fat cells) and starts breaking down fat into fatty acids, which are then burned for energy.
As long as your dietary fat intake isn't too high, a ketogenic diet can help you target stored fat. Plus, it has the added benefit of staying at that optimal blood sugar level you want.
All in all, stick to low glycemic index foods, especially proteins and healthy fats, to stay in that glucose sweet spot.
Watching your glucose levels is the new, smarter approach to weight loss. By making sure you stay at the ideal blood sugar levels, you can stimulate your body to burn more fat instead of storing it.
It's not easy, but now that you know how glucose works and how to track it, you can create a healthy diet that works for your weight goals.
Pick the right foods, monitor your sugar levels, and watch your scale count down