Tag Archives: glycemic index

bad carbs

Are Your Carbs Slowly Killing You?

Let’s go have a burger, but make the bun whole grain please! Ok, so fat is now in and carbs are out. It seems like there’s research to support any diet you choose to follow. Are we getting smarter or just making things so confusing people just throw their arms up in the air, say “screw that” and just eat whatever their heart desires.

But, if you desire your heart, you might want to read this to get some clarity on the controversy.

PURE research

The Prospective Urban Rural Epidemiology (PURE) study, reported in ScienceDaily.com, asked dietary questions to over 135,000 low, middle and high income people over a 10-year period from Africa, North America, South America, Asia and Europe.

There were three parts to the PURE study. One looked at the impact of dietary fats on clinical outcomes while another focused on the consumption of fruits, vegetables and legumes in relation to death, heart disease and strokes. The third component, reported in The Lancet Diabetes and Endocrinology, looked at the impact of dietary fats and carbohydrates on blood lipids and blood pressure.

A summary of the data released in August, revealed that a diet consisting of a moderate amount of fat, fruits, vegetables and legumes and avoidance of a high proportion of carbohydrate was associated with a lower risk of death.

The results were surprising and not in accordance with the current dietary guidelines of dietary fats making up 30% or less of total calories, carbohydrates making up 50% and fats making up the rest while keeping saturated fats to less than 10% of daily calories.

Making sense of the PURE data

Actually, the results do make sense. The lead researcher, Mahshid Dehghan, in an interview with Science Daily said:

“A decrease in fat intake automatically led to an increase in carbohydrate consumption and our findings may explain why certain populations such as South Asians, who do not consume much fat but consume a lot of carbohydrates, have higher mortality rates.”

Many of the participants were low income and ate a diet consisting heavily of white rice and lower on animal products and produce. White rice is a high glycemic food – making blood sugars skyrocket with each additional serving. Animal products are high in protein and produce is high in fiber which slows down digestion and the rise in blood sugar.

If you look at the graph of macronutrients below, you’ll notice that carbohydrates make the blood sugar spike with a steeper parabola than protein and fat. The larger the portion of a simple carbohydrate like white rice, and not combined with much protein or fat, the quicker and larger the blood sugar rise which puts stress on the pancreas to make more insulin to take care of the extra glucose in the blood stream. Eventually, this leads to damage of the arteries and an impaired pancreas, and an earlier death.

macronutrients and impact on blood sugar

Blood sugar and lipid connection

metabolic syndromeHow can high blood sugar affect the fats in your blood stream?

When you eat a lot of processed, white carbs – like white pasta, rice, bread, and crackers – your body quickly digests them and converts them to glucose. Your body can use some of this glucose for fuel, but any extra gets stored in the form of triglycerides.

Findings from the third study also found that a high carbohydrate diet, particularly one with refined grains, was associated with a lower good cholesterol – HDL – which is heart-protective.

A low HDL and high triglycerides are two of the five components of metabolic syndrome – one more of the 5 components and you’ve got heart disease and diabetes in your future.

Glycemic Index and your blood sugar

Glycemic IndexThere are “good” and “bad” carbs. Well, maybe there are some “bad” or unhealthy carbs that really taste good, darn it. I love you Holy Donut. But there are also some “good” carbs that also taste good.

Carbs that are lower in glycemic index are much healthier for you as explained below. Low glycemic foods include legumes like lentils, steel-cut oats, whole grain pasta, fruits and non-starchy veggies. Do you think donuts could taste as good if they were made with whole oat flour and baked instead of fried?

High glycemic foods are all your “white” foods including russet potatoes, pretzels, popcorn, rice cakes and melons and pineapple.

So, a plate of white pasta, which can be as much as four times the recommended serving, with tomato sauce (and most have added sugars), will shoot your blood sugar way up. A large bowl of Rice Chex with milk will do the same thing. Both meals are high in low glycemic carbohydrates and low in protein, fiber and fat.

The rise in blood sugar will cause your body to release extra insulin that will cause your blood sugar to plummet, as you can tell by the graph on the right. In fact, your blood sugar can drop down lower than normal, triggering an adaptive response by your body to get your blood sugar back up to normal. This adaptive response releases epinephrine leading to shakiness, irritability and even a headache. So, you go from food coma to nervous Nellie – that’s an emotional roller-coaster I wouldn’t want to be on.

What you can do

The findings from the PURE study are logical. The important message here is to:

  1. Pay attention to portion sizes of your carbohydrates – use the food label to become aware of a serving size.
  2. Make at least half of your carbs low-glycemic, moving away from the “whites”.
  3. Include a source of protein – low-fat Greek yogurt, low-fat cheese, poultry, fish or lean meat with your meals and snacks.

 

Are You Always Hungry? – Consider Glycemic Index

You just ate a couple of hours ago and you’re hungry again.   You had a huge plate of Ramen noodles and now you are starved, ready for a nap and don’t feel quite right.  These are common feelings that can occur after eating foods with a high glycemic index.  Glycemic Index (GI) is a system that ranks food made up of carbohydrates on a 100 point scale based on the impact the food has on blood sugar.  The higher the number, the more rapidly the blood sugar spike after consuming it.  These rapid rises in blood sugars occur after eating carbohydrates that are easily digestible.  In general these are the carbohydrates that have some processing and have been stripped of their fiber like mashed potatoes, white pasta, white rice, puffed rice cakes, pretzels and pulp-less OJ.

High Glycemic Index Foods Cause and Insulin Spike

There are many factors that determine the glycemic index but basically, the more quickly a food is digested and absorbed the more rapid the blood sugar rise.  If the serving of carbohydrate is excessive and not eaten with foods that may slow down digestion the rise can be quick.   The pancreas senses the sudden rise in blood sugar and releases large amounts of insulin to keep the blood sugars in a healthy range.  Insulin helps some of the sugar or glucose be used for cell function but any excess is sent into fat storage and circulates in the form of triglycerides in the blood stream.  The surge in insulin can also make blood sugars drop very quickly which can affect the nervous system.   This may cause shakiness, fatigue, a headache and even anxiousness.  It also can make us feel hungry as a way to signal to our body that we need food to get those blood sugars back up to a better range.

Choose Low to Medium GI Foods For Fullness and Weight Loss

If you focus on foods that are lower in GI then you will avoid the insulin spike that leads to fat storage and hunger.  The easiest way to remember this is to think of what I call “the sludge factor”. Whole grains, beans, nuts, fruits and vegetables are the foods that make up the sludge factor.  These foods are high in fiber.  Have you ever seen what happens to a glass of water when you let Metamucil sit in it for too long?  It gets thicker and goes down much more slowly.  When you eat foods that are high in fiber, the fiber absorbs the moisture in the digestive track and becomes thicker.  Now include some fat, hopefully healthy fat from fatty fish like sardines and salmon, flax seed, olive oil or avocados, and you further prolong digestion which will extend the fullness feeling. Protein also adds to the the fullness factor, slowing down the digestion of carbohydrates.  IMG_0514 Include some healthy protein found in fish, meats, Greek yogurt, eggs, low fat cheese and even some grains and beans and you have extended the fullness factor even further!   That’s why a meal of salmon, a serving of sweet potato or my Three Bean salad and a non-starchy vegetable like broccoli or asparagus will keep you full for four to five hours.  It’s also why a breakfast of some scrambled eggs and whole grain toast will keep you fuller longer than a bowl of most cold cereals because they have little to no fiber, fat or protein and deliver way too many high glycemic carbs.

Low Glycemic Index Foods (0-55)

  • 100% stone ground wheat
  • steel cut or old fashioned oats
  • most fruits and non-starchy vegetables
  • sweet potatoes, peas, legumes, lentils
  • whole grain pasta, converted rice, bulgar, barley

Medium Glycemic Index Foods (56-69)

  • whole, rye or pita bread
  • brown, basmati, and wild rice and couscous
  • quick cook oats

High Glycemic Index Foods (70+)

  • melons, pineapple
  • white bread, rice cereals, instant oatmeal
  • short grain rice
  • macaroni and cheese from mix
  • saltines, rice cakes, popcorn

Other Factors That Affect Glycemic Index

If there is anything to spotlight how much food is chemistry and therefore healthy medicine when thoughtfully chosen, it is the information in this paragraph.  Below are some of the other considerations that impact  glycemic index:

  • ripeness and storage time – a riper banana has a higher glycemic index than a greener one.
  • cooking time – al dente pasta has lower GI than pasta cooked longer.
  • variety – converted long grain rice has lower GI than brown rice which has lower GI than white rice.
  • processing – mashed potatoes has higher GI than a whole potato.
  • cooking method – most steamed veggies have a lower GI than roasted.
  • temperature – a cold potato – like in a potato salad has a lower GI than a hot potato.
  • food combinations – the presence of fat lowers the GI of the food.
  • surface area – a puffed grain like in a rice cake has a higher GI than a grain of rice.

Glycemic Index versus Glycemic Load

To further complicate things, Glycemic Load(GL) is another calculation that takes into consideration how the serving size of carbohydrates affects blood sugars.  For example, watermelon has a high GI but a typical serving is a lower GL so it will not cause as much of a spike unless you are eating half a watermelon.  Conversely, a huge serving(GL) of steel cut oatmeal(low GI) can have a bigger impact on raising blood sugar than a very small serving of instant oatmeal.  So the food portion and the type of carbohydrate both impact blood sugar.  Those large boxes of Skittles or Gummy Bears at the movie theater may have no fat but they are going to spike your blood sugar, which will spike the insulin response and only lead to weight gain over time if eating other high GI and GL foods excessively over time.  Furthermore, it will leave you feeling hungry, tired and perhaps even a little shaky and irritable.  Is the short term pleasure worth the long term impact?

GI simplified

Does all this seem too complex?  Again, just visualize the Plate Method that moderates portion sizes while getting all the components of fullness factors along with nutrition.  Half your plate should be made up of non-starchy veggies, one quarter of your plate made up of lean protein and the other quarter made up of a starch or carbohydrate.  Make that starch a whole grain, a bean salad, brown or converted rice, or a potato and you can get the picture.  Choose the right carbs(GI) and the right amount(GL) and make cooking at home fun.   Realize that you are worth it and your body will pay it forward.  And if you really want that sweet, then at least eat it with a meal when there’s also fiber and protein to create the sludge factor.  And then go brush your teeth, lock the kitchen doors and turn out the lights!

Click here to learn more and look up the GI and GL of many foods.