It’s about time…weight, that is

Posted by Liz on Apr 5, 2010 in weight, weight gain | 5 comments

Findings from a new study suggest that time of day may play a critical role in how much weight you do or do not gain. In fact, you may be better off eating fat first thing upon waking as opposed to at the end of the day.

Mind you, this study was conducted in mice and not humans, so it’s way too early to know for sure. However, what they found that was when mice were fed a high-fat diet constantly throughout a waking period, they did not gain substantial amounts of weight, body fat or develop unusually high blood sugar. In fact, they appeared to adjust their metabolism accordingly. However, when mice were fed either high fat or carbohydrate rich diets at different times during the day, the paradigm shifted and their bodies were not always able to adjust metabolically. Here’s the skinny:

• Mice who ate a calorically-rich, high-fat meal immediately following the four hours after waking were able to adjust their metabolism and the amount of energy they used up so that weight remained normal. However,
• Mice who ate a calorically-rich, high-carbohydrate meal in the first four hours after wakening and then a high-fat meal four hours before rest had gained excessive amounts of weight and body fat, had blood sugar abnormalities associated with diabetes, and had increased levels of fats in the blood. Ironically this occurred regardless of total daily calories or total calories from fat.

The researchers say there is plenty of evidence showing that people who skip breakfast tend to have higher a body-mass index (BMI), as do people who engage in night eating. They also note that like the mice in the study, our circadian clocks do play a huge role in both our appetite and how we expend calories during the course of a day. Although individuals tend to vary how and what they eat throughout any given day, there is a tendency to eat carbohydrates early in the day and higher fat or more calorie dense meals later. So, it’s possible by reversing this pattern, we may be able to affect how we respond to carbohydrate rich meals (and associated weight gain) later in the day.

Granted, only time can tell and it’s essential to repeat this study in human. Plus there’s another fact that women in particular need to be aware of: hormones and age play a critical role in controlling metabolism, and how, when and where we gain weight.

Right now, the best strategy is to eat healthy foods, unsaturated fats and exercise. But if you are craving bacon, you may want to have it in the morning and not in a BLT or wrapped around a scallop later in the day.