3. Hunger
Hormones trigger your body to eat when it’s hungry and to stop eating when you’ve had enough; it’s a complex process. Leptin is a hormone created in adipose tissue that is closely linked with insulin in sensing how much sugar is in the blood. When it reaches a certain level, leptin production increases to tell your brain to stop eating.
Leptin and insulin work on opposite sides of the same process and regulate each other. When insulin increases, leptin decreases and vice versa. If there’s an imbalance with insulin or cells become resistant to it, leptin production can decrease and you constantly feel hungry. (11)
Furthermore, it’s possible for cells to become resistant to leptin; you feel hungry even if your stomach is full and your blood sugar is at the appropriate level. This can lead to over-eating and weight gain. The more weight you gain, the less sensitive to leptin your body becomes.
4. Hypertension
Insulin resistance has been repeatedly established as a contributor to high blood pressure. When uptake of insulin is reduced, absorption of salt by the kidneys is affected, resulting in sodium overload and consequential hypertension. (12) This can occur in people that don’t have diabetes: blood sugar levels might be okay but one of the things that insulin does is open blood vessels. Constricted blood vessels make the pressure rise. (13)
When cells are resistant to insulin and insulin production remains at a normal rate, insulin can accumulate in the blood in excess relative to the amount of glucose. This condition is called hyperinsulinemia. Many studies have associated hyperinsulinemia with hypertension, although the causes may vary.
Some suggest that hypertension due to other causes lead to insulin resistance; others have found the reverse to be true. It all depends on the individual and many risk factors. (14) All studies agree on one thing: high blood pressure is an indicator of insulin resistance. When insulin sensitivity increases, the incidence and risk of hypertension decrease. (15)
5. Lethargy and fatigue
Chronic fatigue is one of the by-products of diabetes because the body isn’t burning energy properly. With pre-diabetes, reactive hypoglycemia (too little blood sugar) can occur after a carbohydrate-rich meal. You get a surge of energy immediately after eating, insulin responds by spiking to manage the food intake, then energy crashes. This can leave you feeling sluggish and sleepy. Eating in this pattern over time, with insulin spikes and crashes, can lead to insulin resistance. (16)
Most people with diabetes are overweight or obese. Excessive weight reflects diet and lifestyle factors that naturally feed into fatigue: lack of exercise and nutrient-poor foods. (17) Excess omega-6 fats can induce depression, which exacerbates feelings of fatigue, decreased physical activity, and consequential insulin resistance.
Eating corn oil has been specifically shown to lead to lethargy and the development of insulin resistance. (18) Use grass-fed butter, olive, sesame, coconut, and avocado oils instead.