Insulin is an important hormone that facilitates the movement of glucose into our cells after eating. When this mechanism is working as it should, we eat and blood sugar begins to rise. Insulin is released to allow the glucose to get from the blood into our cells to provide them with energy. As blood sugar falls, insulin release will slow and eventually level out along with blood sugar. Avoiding large fluctuations in both insulin and blood sugar is crucial to feeling your best.
Insulin resistance is one of the earliest signs of blood sugar dysregulation, and a major contributor to most chronic diseases, including obesity. It involves the tissues in our body becoming less sensitive to insulin. In the earlier stages, the body requires more insulin to control blood glucose. Overtime, higher levels of insulin contribute to further resistance, and in the later stages the insulin is not sufficient, and blood sugar begins to rise. This is a huge concern in our modern world, and its incidence only continues to rise. Chronic high levels of insulin impair fat oxidation leading to weight loss resistance, and increase blood sugar and inflammation contributing to diabetes and cardiovascular disease.
Treating insulin resistance involves a combination of lifestyle and dietary factors. Here we are going to focus on dietary interventions to increase sensitivity to insulin, therefore lowering insulin and combatting weight loss resistance.
There are two important things to consider here – what you eat and when you eat.
The What
The foods you eat will directly alter the fluctuations of blood sugar and the insulin load required. Foods that tend to result in higher insulin release over time will contribute more to resistance. Carbohydrates are the most common contributors to insulin as they create larger spikes in blood sugar. To note, any carbohydrates that are fried along with oils/fats will have a compounding effect (hence why most processed carbohydrates, and baked goods are major contributors to insulin resistance). The quality and quantity of carbohydrates is key. Simple carbohydrates such as those found in flours, sugars, starches and fruit juices/pops will contribute much more to overall insulin resistance than complex carbohydrates will. What makes a carbohydrate more complex is the higher percentage of fibre. Fibre dampens the blood sugar spike, and less insulin is needed. Fibre also helps to keep you fuller longer. These complex carbohydrates include non-starchy vegetables, and berries. Protein, although insulin stimulating, is necessary for our bodies repair mechanisms, satiety and helps to blunt blood sugar responses from carbohydrates. Having protein at each meal has been shown to aid in weight maintenance. Lastly, healthy fats will also help blunt the blood sugar response, improve satiety, and they have a very minimal effects on insulin. Fats should be consumed through healthy sources such as fatty fish, nuts/seeds, avocados, and healthy oils like olive oil. It is a simple rule of three, when eating ensure to have:
- Fibres through complex carbohydrates
- Proteins from plant or animal sources
- Healthy fats
The When
The timing of your meals can substantially influence levels of insulin as well. Food consumption, specifically glucose and certain amino acids are the trigger for rising insulin levels. Therefore, when someone is already insulin resistant, it takes longer between meals to bring it back to baseline. More frequent meals keeps insulin levels high all day long which can keep us stuck in storage mode, making fat burning more difficult. Longer times between meals helps to increase sensitivity to insulin, which keeps insulin and inflammation low and prioritizes fat burning. This is also true for the fasting window overnight, longer fasting allows insulin more time to decrease before your first meal the following day.
It has been shown that eating outside of the normal feeding window (which is during the day), results in an increased risk of cardiovascular and metabolic diseases. That is likely due to the reduced glucose tolerance when eating late at night. This means that blood sugar and insulin will increase to higher levels with the same foods than if you had them during the day. It may also be important when you consume carbohydrate-rich meals. Higher carbohydrate/ sugary breakfasts are associated with a worse insulin response throughout the rest of the day.
Key Take-home Points
- Avoid processed/sugary carbohydrates, especially in isolation and always include healthy fats, protein and fibres in each meal and snack
- Avoid grazing all day long, and minimize snacking between meals
- Have a minimum of a 12-hour overnight fast, and avoid eating late at night
The treatment of insulin resistance should include a holistic approach. Diet is only one piece of the puzzle and those with insulin resistance should have a treatment plan that includes physical activity, stress management, sleep optimization, and individualized supplementation when necessary.
Resources:
PMID: 28257081
PMID: 31756065
PMID: 30925707
