Too much food makes us fat. By this logic, it makes sense to combat obesity with less food. While this simplistic energy in, energy out algorithm has driven weight loss diets for many years, perhaps there are more sophisticated ways to address weight loss. It’s not just the amount of food we eat, but the type. Research suggests some foods assist in weight loss, more so than others.
Brown Adipose Tissue
Thermogenesis refers to the energy our bodies expend, due to the food we eat. It can be broken down into two main categories; adaptive and obligatory. Obligatory energy losses are those used for gut movement, nutrient absorption and other activities necessary to digestion. These energy losses cannot be modified to any great extent.
Adaptive energy losses are of more interest to those wanting to lose weight. This is the energy expended due to brown adipose (fat) tissue activation. Brown adipose tissue is ‘normal’ white adipose tissue’s friendlier cousin. Unlike white tissue, brown tissue expends energy, rather than storing it. This extra energy expenditure, can be used as a tool in weight loss. Unlike obligatory losses, adaptive losses are heavily influenced by the food we eat. Certain foods and food constituents stimulate the release of noradrenaline which then acts on receptors on the brown adipose tissue, to activate it. This results in energy expenditure in the form of heat. Current thermogenic foods raise energy expenditure by a modest 2-5%. However, with further research, nutrition scientists think we could raise this to 10-15%, which will have staggering effects on weight loss (ncbi).
What to Eat
Here’s the million-dollar question, what are these foods that activate brown adipose? While research hasn’t discovered all thermogenic foods, and there is still much we don’t know, we do know of a few bioactive substances which may assist in weight loss. These include, capsinoids (capsicum, chilli and cayenne), methyxanthines (coffee), catechins (green tea), polyphenols (cocoa), minerals, argenine (turkey) and some carbohydrates and fat. This is by no means a comprehensive list. The most promising compounds are those of the capsinoid variety. Anything peppery or spicy is thought to have brown adipose activating properties.
Aside from food, we can activate brown adipose by cold exposure. This gives some substance to the idea behind cold showers being good for health. However, the research to support this is based on an intervention where subjects are exposed to two hours of cold exposure daily. Unless you are taking extremely long showers, you might be shivering through your shower for nothing.
Treatment or Preventative?
Brown adipose tissue is most active at birth. Slowly but surely, it becomes less active as we enter adulthood. Some studies show that by maintaining a healthy body weight, eating well and exercising, it is possible to preserve brown adipose activity. This means that brown adipose tissue will be better stimulated in already lean individuals, suggesting that brown adipose is mainly helpful in obesity prevention, rather than reversal. Furthermore, there are ethnic differences in brown adipose activation, that need to be further investigated.
It would seem we have two options, burn our tongues with capsinoids, or freeze our bodies. Neither of these options are particularly pleasant, and may not even work in some individuals to any great extent. Activating brown adipose was thought to offer an easy out for obese patients, but with the research being forever inconclusive, and its activation not being entirely ‘easy’, it seems like the conventional healthy diet and exercise wins out once again. Thermogenic foods should be added as an afterthought to diet, and not be relied on as a weight loss tool.
If you are interested in brown adipose tissue and want to know more, this is a good summary of the research.
The feeling of fullness arises by 2 mechanisms. The stretch of food on the walls of the stomach and intestinal tract, is one. This sensation is known as satiation and signals the completion of your meal. The feeling of not being hungry for the hours following a meal is known as satiety. Satiety is controlled by hunger hormones. What you eat, can affect the hormonal condition, and thus affect satiety too. Some foods that help promote satiety hormones include protein and fibre. Therefore, consuming meals that are high whole grains and veg, and pairing them with a lean protein source, will aid in your weight loss journey.
For a long time, and still to this day, we like to think of weight as a simple energy algorithm. Energy in vs energy out. The logic says that is we expend more energy than we consume, then weight loss will occur. This is easier said than done. The hormonal environment of the obese individual favours food consumption and energy storage. Therefore, this algorithm doesn’t always hold true. It is important to eat healthy foods and combine exercise, for weight loss and not rely on any one diet strategy. Furthermore, each individual is very different and it may take some trial and error to determine the weight loss method that suits you best.
Obesity plagues our society. Any which way we look at it, we can’t deny the benefits of a healthy diet and exercise. Novel nutrition ideas, like thermogenic foods should be used as an extra helping hand in weight loss, but only paired with a healthy diet.