Overweight? What You Eat Matters More Than When: Dr. Kevin

Oatmeal Breakfast

Timing of Your Meals MattersThe issue of just when you should eat carbohydrates has been discussed and debated because there has been some speculation that when you eat carbohydrates impacts your weight loss goals.

Although experts agree that carbohydrates are important and should not be avoided, many people say they should be consumed in the morning. Bob Harper, a fitness trainer, tells his clients to “front load their carbohydrates.” When you eat carbs earlier in the day, however, “you’ll know you’ll have time to burn them off” with exercise, he said.

Well, I am not sure that this is really quite correct. If you are dealing with people who are overweight or obese and trying to lose weight, these rules do not apply at all. These folks all have a certain degree of insulin resistance so feeding them a large carbohydrate meal at any hour is not a very good idea.

It will just encourage fat accumulation and blunt any fat oxidation later from exercise. It’s more important to consider the type and quantity of carbs you eat and combine them with some protein and healthy fat.

For your carbs in the morning, I suggest oatmeal. This is a low-glycemic carbohydrate that will raise blood sugar very slowly and keep it constant for hours. If you eat a large meal of carbohydrates like corn flakes or toast and jam, this will raise blood sugar quickly and produce a large influx of triglyceride into fat cells. Any amount of exercise performed later will have no effect upon this fact—disastrous for your weight loss goals!

Other trainers like Gunnar Peterson, who works with celebrities, recommends that his clients skip carbs later in the day because “foods like rice, grains, pastas, oatmeal, and potatoes make your body retain water which blurs, to a certain degree, definition and muscle separation.”

Although this really doesn’t have anything to do with weight loss, there are a few items here that also need clarification.

Yes, carbohydrate molecules do attract water molecules into cells for storage. For example, glycogen is the storage form of carbohydrates in muscles and liver but these are intercellular storage sites which require water. Athletes that carb-load can increase their muscle hardness and definition by doing this. The type of water retention that Peterson speaks of is extra-cellular water retention which is not the case with proper carbohydrate nutrition.

Other experts, like dietician Shira Lenchewski explains, our bodies’ circadian rhythm, or “internal time-keeping system,” plays a huge role in “metabolic and hormonal changes over 24-hour cycles.” Carbohydrate metabolism fluctuates around the circadian cycle, meaning that “[carbs] are burned more efficiently in the morning than at night,” she said. For clients trying to lose weight, she recommends that the largest meal (higher in carbohydrates) is breakfast, while the rest of your meals should be “trending smaller as the day goes on.”

Although this assertion is partially true, if you are overweight or obese, the types of carbohydrates, and what you eat them with, is more important than when you eat them. The key to weight management is controlling insulin secretion, keeping your blood sugar low, and encouraging fat oxidation of stored body fat through exercise and meal planning.

According to some interesting research conducted on six healthy lean adults who ate meals throughout the day composed of either high-glycemic foods, low-glycemic foods with 60% of the energy consumed in the morning or in the evening meal, insulin sensitivity was much worse and blood sugar was much higher in those consuming the high-glycemic, higher-energy evening meals contrasted with smaller, low-glycemic meals consumed in the morning.

Research indicates that it is the glycemic load of the foods and when they are eaten which greatly influences blood sugar and insulin sensitivity. Consuming lower-glycemic carbs in smaller meal sizes beginning earlier in the day and avoiding large, high carb-dense meals in the evening seems to be the best way to manage your food intake for weight loss.

“Eat carbs, lose weight: it’s all about timing,” Yahoo! web site, November 7, 2013; http://ca.shine.yahoo.com/blogs/healthy-living/eat-carbs-lose-weight-timing-003400929.html,last accessed November 11, 2013.
Morgan, L.M., et al., “Effect of meal timing and glycaemic index on glucose control and insulin secretion in healthy volunteers,” Br J Nutr. October 2012; 108(7): 1,286-91.