It can get complicated when you want to create a self-care routine, eat healthily, and lose weight. Making lifestyle changes involves the body, mind, and environmental aspects. This article focuses on the body, the physiology of eating, metabolism, and weight regulation. More specifically, we explore the hormone insulin and its function in weight management. And most importantly, discover what dietary and lifestyle changes you can implement to keep your insulin level and weight healthy.
When you know what happens inside your body, you can make better food and lifestyle choices. You can harness this knowledge and create a plan that makes sense and works.
The process of eating and energy production
We eat to provide energy and nutrients for our bodies. In general, scientists split nutrients into two categories: macro and micro-nutrients. Macronutrients are fats, proteins, and carbs. And vitamins, minerals, and phytonutrients are examples of micronutrients.
Metabolism is all the chemical reactions that make or burn energy in the body. Your body’s metabolic processes use macronutrients and turn them into energy. There are two metabolic states: Anabolic or Fed state and Catabolic or Fasted state.
Fed state
After a meal, you experience a flood of nutrients coming into the bloodstream. Too much to burn right there and then. So some of those nutrients are going to be stored for later use. Then we easily convert all excesses into fat and a bit of glycogen. The critical characteristic of this state is the storage of nutrients.
Fasted state
About three hours after a meal, nutrients are no longer in our bloodstream, and we transition into the fasted state. We tap into stored reserves to provide energy to the tissues until the next meal. The vital characteristic of the fasted state is the burning of stored nutrients, aka fat.
Hormones regulate metabolism
We fluctuate between fed and fasted states without any effort or knowledge of it. Our hormones – insulin and glucagon – regulate these transitions and metabolism. Both are always present, but their ratio determines whether we are in a fed or fasted state, mostly storing nutrients or burning the stores.
When we eat, the pancreas secretes insulin. One of the most important messages that insulin sends to the cells is that nutrients are plentiful and that it’s time to store them. Insulin is what we call an anabolic (storage) hormone.
Any food intake triggers insulin secretion. The amount of insulin will vary. It depends on what we eat, how much, and the macronutrient composition of our meals. Among the three macronutrients – fat, protein, and carbohydrates – carbs trigger the most significant release of insulin.
The delicate balance of weight regulation
About 2-3 hours after we eat, the food is digested, absorbed, and packed away from the bloodstream into our cells. As a result, our blood glucose levels go down, and insulin levels decline. Low insulin and slightly elevated glucagon levels signal the cells that it’s time to switch from the fed to the fasted state.
Yes, other hormones participate in this vital process of storing and burning nutrients, but insulin is the key. A low insulin level gives “permission” to fat cells to break down fat molecules, send them out into the bloodstream, and provide the body with energy between meals.
To summarize this straightforward process of storing and burning: we eat, the insulin goes up, we store nutrients, the insulin goes down, then we break down and burn stored nutrients. That’s how the healthy physiology of weight maintenance works. If we spend more time burning, we lose weight. And if we spend more time storing, we gain weight.
When insulin levels stay too high
It’s easy to skew the balance of weight maintenance toward weight gain or loss. When insulin secretion increases or stays up for too long, our metabolism gets out of balance, and we gain weight. Our lifestyle and food choices affect our metabolic health and insulin secretion:
The frequency of eating
A common advice is to eat small portions throughout the day to control your appetite and weight. If you graze, your insulin levels stay elevated throughout the day. Even if you eat just a handful of grapes, an apple, or a couple of crackers, you switch to the fed state. From the calorie counting standpoint, it’s not a big deal, but from the hormonal regulation of weight – not a good idea.
Carbohydrate-rich diet
A diet full of processed carbohydrates like crackers and cookies, fruit juices and sweetened drinks, sweet yogurts and cereals – all these foods push our insulin levels through the roof.
Sedentary lifestyle
Physically active people, the study shows, regulate their hunger and energy needs better than sedentary people—their hunger and food intake match what they burn better.
The hunger of sedentary people doesn’t go down to match their energy needs. Their muscles become less efficient at burning nutrients. And it leads to a more extended return to the fasted state.
Health consequences of high insulin
When insulin levels remain high over extended periods, it leads to three unfortunate outcomes. First, the delicate balance of weight maintenance is skewed toward storing, and we start gaining weight.
Second, high insulin levels increase hunger! When insulin levels are high, fat – this excellent energy source – is “locked” inside the fat cells. It’s unavailable to the rest of the body, and many tissues become semi-starved, making us hungry.
And third, our cells get less sensitive to this overabundance of insulin, leading to insulin resistance. As a result, the pancreas has to increase its work and produce more and more insulin to accomplish its mission, perpetuating the cycle.
Insulin resistance can create serious health consequences if this continues for months and even years. The health consequences of insulin resistance are excess weight, elevated blood sugar, prediabetes, and diabetes. Recent studies show a connection between too much insulin and acne, heart disease, and Alzheimer’s disease, to name a few.
Lifestyle and dietary choices that revert insulin resistance
To break the cycle – to reduce cells’ resistance to insulin, lower insulin levels, and lose weight – we need to make lifestyle and dietary changes:
- Limit your intake of processed carbohydrates. Either limit potatoes, rice, corn, and all foods made with flour like bread, pasta, and baked goods. Or explore a more complicated approach and choose foods low on the glycemic index and glycemic load.
- Include vegetables, protein, and fat in most meals to balance out the carbs.
- Eat fewer times a day. A classic three-meal schedule will work. Give your body breaks between meals that are longer than three hours.
- Intermittent fasting is a very effective way to establish insulin sensitivity. You can start by making your overnight fast longer. Gradually move your dinner to an earlier hour or your breakfast to a later hour.
- Walk or move some other way after meals. Even a 10-minute walk helps reduce your blood sugar and insulin.
References:
- D. U. Silverthorn, Human physiology – an integrated approach, 5th edition, 2010, Pearson Education, San Francisco
- G. Taubes, Good Calories, Bad Calories, 2008, Anchor Books, NY
