AP Biology class blog for discussing current research in Biology

Tag: weight loss

Exercising in the “Extremes” (Hot or Cold) Does Not Necessarily Lead to Weight Loss. Here’s What Does:

As it has been a trend for years, many believe the claim that exercising in cold or hot temperatures will cause you to burn more calories, leading to weight loss. Although many believe this, it is not actually true nor an efficient way to lose weight. 

First, let me take you through how humans burn calories. The most common way you burn calories is by your metabolism. According to the Mayo Clinic, “metabolism is the process by which your body converts what you eat and drink into energy. During this complex biochemical process, calories in food and beverages are combined with oxygen to release the energy your body needs to function.” Metabolism can also be classified as your basal metabolic rate, or how many calories your body uses to carry out these functions. The basal metabolic rate makes up about 60 to 80 percent of your total energy expenditure and calorie loss. In addition to your metabolism, a portion of your energy expenditure and therefore loss in calories comes from thermogenesis: the way in which the body produces heat. Thermogenesis makes up 10% of total energy expenditure, leaving only 10-30% for physical activity (which, in reality, is not a lot). 

In terms of that last 10-30%, the body burns the remaining calories by shivering (if cold) or by exercising. Shivering and exercise are viewed as the same inside of the body as they both trigger the activation of what is called brown fat or brown adipose tissue. When you shiver, your muscles involuntarily contract to generate warmth to regulate homeostasis but it also triggers “muscles to secrete a hormone that stimulates energy use in brown fat cells” (according to the National Institute of Health). The same thing happens when you exercise! In another example, brown fat helps infants who don’t know how to shiver yet regulate their body temperature. 

While brown fat burns calories to generate heat, something called white fat stores calories as heat / insulation to keep you warm. As you can assume, It is better to have more brown fat than white fat as large amounts of white fat, and this insulation, can lead to obesity. This is because white fat stores energy in large lipid droplets throughout the body. On the other hand, brown fat contains smaller lipid droplets and higher amounts of mitochondria. This increase in mitochondria causes an increase in ATP or energy production and therefore increase in energy expenditure and calorie loss. 

So how is this related to energy expenditure and calorie burning, you ask? Many people believe that you can burn more calories in the cold because of this brown fat. Although this is true, you need at least 2 hours in 66 degrees fahrenheit (or lower temperature) in order to see the extreme effects of the body activating the brown fat and burning more calories. On the other hand, many believe that you will burn more calories in the heat (or hot conditions) because sweating more must mean your body is working harder and losing more calories, right? This is not always the case – releasing more sweat doesn’t always mean you are releasing more energy and losing more calories. Rather, in the case of very hot conditions, like hot yoga for example, the sweat you are releasing only causes you to lose more water, not calories.   

There are pros and cons to any type of exercise, but ultimately choosing to work out in hot or cold conditions to promote weight loss, may do more harm for you than good, especially if you are new to the exercise scene as your body may not react well to these temperatures. To promote weight loss, you must be in a calorie deficit –  burning more calories than you are in consuming. This is the best and really the only way to lose weight (along with exercise). 


The Ketogenic Diet: Potentially Life Threatening?


What is the keto diet?

The ketogenic, widely known as ‘keto’, diet has become a popular diet for weight loss among adults in the US. Although it was originally curated to reduce seizures in children, many use low-carb, high fat diet to slim down. The keto diet requires that you eat 75% of daily calories from fat, 5% from carbohydrates, and 15% from protein. The average person gets about 20-35% of their daily calories from fat, and dieticians recommend you get about 50% carbs from your meals, so is this diet safe?


Triggering Ketosis

The keto diet causes the body to switch from burning glucose (produced by carbs) to burning ketones (produced by fat), triggering ketosis. During ketosis, when the body doesn’t have enough stored glucose to create energy, ketones are released. Ketones are results of the body breaking down fat for energy. Throughout ketosis (the release of ketones), the body breaks down dietary fact and then body fat, resulting in the sought after fat loss of the keto diet. Ketosis is normal, but can pose a threat to those with Type 1 or 2 Diabetes as lack of insulin can cause a build up of ketones and glucose in the blood. The pros of ketosis include increased brain performance as ketones cross the blood-brain barrier and physical energy. Adverse effects include fatigue, irritability, and feeling “foggy,” so is this ketogenic diet all that safe? 


What happens when glucose is reintroduced? 

Led by associate professor Jonathan Little  in the School of Health and Exercise Sciences at UBCO, researchers at the UBC Okanagan campus conducted a study to test how the body would react when reintroduced to glucose. As test subjects, they used nine healthy males and put them on a high fat, low-carb diet (ketogenic)  consisting of 70% fat, 20% protein, and 10% carbs, for seven days. They were each given a 75 gram glucose drink before and after the week long trial and the results were astounding! Biomarkers (indicate the beginning or ending of a process within the body) in the test subject’s blood signaled damage to vessel walls caused by a sudden surge in glucose levels.Professor Little attributes these biomarkers to the body’s metabolic response when exposed to excess sugars. This process may cause blood cells to shed and possibly die,posing a potential threat for ketogenic dieters!


The verdict?

The researchers at UBC don’t recommend the keto diet as it may be undoing “some of the positive impacts on their blood vessels.” In short, the healthiest option for losing weight is a sustainable, colorful diet and good ‘ol exercise. It’s important to listen to, and act according to what your body needs/is telling you; not just the new fad. 


Have you/would you ever try the ketogenic diet? Comment down below!





Click below for Keto recipes!:



The New Way to Diet

The New Way to Diet 

Today, obesity is a global epidemic effecting millions if not billions of people world wide. Whether it be a few pounds or even a couple hundred pounds, there are countless people out there looking for a way to drop excess weight. Some they try dieting and altering what they eat and others revert to more serious methods, such as surgery. Recently a new procedure has been created that can help those suffering from obesity. Called  GECA or (gastric artery chemical embolization), this surgery can change the lives of millions of individuals.

* Click on image for link to flickr page

GECA is a surgery much safer than a liposuction that can literally make you less hungry  This relatively simple surgery is carried out by blocking off an artery that leads to the stomach. Doing this cuts off the blood supply to a certain section of the stomach that can produce the hormone called gherlin. This hormone controls our cravings to eat food and the sensation we call ‘hunger.’ Removing this hormone from our bloodstream would take away the desire to constantly eat. We would still be hungry, but just for less. With the desire to eat dissipating  one’s intake would go down and, with some exercise, the pounds would drop easily.

What do you think of this new procedure?

Source Article:




Powered by WordPress & Theme by Anders Norén

Skip to toolbar