It’s been awhile since I blogged, so I thought I’d write about something that’s been taking up a lot of my time recently, diet plans and nutritional research. I’ve always been interested in how certain foods can have an two different effects on different people, furthermore, how despite constant training and various adaptions to keep losing weight people still find themselves stalling and eventually falling back into bad habits.
So I’ve been reading into a lot of new studies on weight loss and activity levels in an aim to get to grips on this particular subject. One study in particular stood out, now, I’ll attach a link to study but I’m not going to reference as I speak as it’s a blog, not a research paper.
“The study aimed to look at weight loss in overweight sedentary woman across four groups: a control group that did no exercise at all, a “low” group that did 72 minutes (4 KKW) of exercise per week, a “moderate” group that did 136 minutes (8 KKW) of exercise per week, and finally, a “high” group that did 194 minutes (12 KKW) per week. Participants in all groups were asked to make no changes their dietary habits over the course of the 6-month study.
Based on total energy expenditure measured throughout the week and self-reported caloric intake, researchers calculated a predicted weight loss (how much weight an individual should be theoretically lose given the simple calories in, calories out formula). At the end of the study, they compared this prediction to how much weight was actually lost between the different groups.
Most people would assume that the group that did the most exercise would lose the most weight, but that wasn’t the case at all.
As you can see from the graph, the group that did the greatest amount of weekly exercise actually lost less weight than the group that did the moderate amount. Even more interesting, the high group actually ended up losing almost the exact same amount of weight as the low group, 1.5kg compared to 1.4kg.”
So what does this all mean? it means that the group that exercises for 194 minutes per week— a little more than three hours— didn’t actually get better results than the group that only exercised a little more than one hour per week. In other words, they did three times as much work for the same results.
Why is this? Surely higher levels of activity will equate to greater weight loss and better results? In fact, a LOT of research is showing the opposite within these populations where a drastic increase in activity actually leads to a capped weight loss. It should be noted that there is still weight loss, this study is not saying that If you work out more, you won’t lose the weight, but the hypothesis that increased activity (3hrs+ a week) did NOT result in any more weight loss than the 1 hour a week group.
So why could this be? In a previous blog, I discussed metabolic hormones and their role in weight loss, weight gain and muscle retention. This is where Dopamine comes into the fray. Dopamine is a chemical compound that is linked with “pleasure” or “reward” stimulus—When you eat chocolate or something sweet, dopamine is released by the brain and it gives you a feeling of pleasure and can even be found to reduce stress.
But everything need to be in balance, this is called energy homeostasis and it is the process in which both energy expenditure and energy intake is regulated in order maintain balance, this is hugely important and drives many mechanisms within the body to react to stimulus. A good example is your body temperature, if you’re sat in a roasting hot room, your body temperature will also rise, now this could be deadly as our bodies only operate within a very narrow temperature range, if we go below or above we lose biological function and, well, die. Biological systems like those of your body are constantly being pushed away from their balance points. For instance, when you exercise, your muscles increase heat production, nudging your body temperature upward. Hence sweat. Similarly, when you drink a glass of fruit juice, your blood glucose goes up. Homeostasis depends on the ability of your body to detect and oppose these changes.
To regulate energy homeostasis, dopamine is involved in driving any behaviours related to both moving (energy expenditure) and eating (energy intake). This is an evolutionary construct, if we didn’t have motivation to keep up, move and eat then we simply wouldn’t be here.
While dopamine’s role in driving moving and eating behaviours is crucial to survival, it can also sabotage our weight loss goals when we try too hard to move more and eat less. As I discussed in my previous article on why our obsession with high-intensity has failed us all, moving too much can quickly lead to a recovery debt.
So how does this fit in with exercise? Well in previous blogs I’ve stressed the point that being in a constant caloric deficit where you not only drastically restrict calories whilst going all out in the gym, your body can fight back against it. A recovery debt occurs when you spend so much energy being physically active and dealing with the stress of life that there’s not enough energy left over for resynthesizing new muscle. It’s vitally important that you realise that your metabolism is limited in how much energy it can only produce each day, it’s not as simple as shovelling in as much food as possible and thinking “that’s enough to re-fuel” that 700cal workout i did. Your brain is has to prioritize where to distribute this limited resources. Regardless of what ANY supplement tells you, whenever you put yourself in a caloric deficit, quite simply you are forcing your body to start breaking down its own tissues for energy. Ideally, this comes from fat stores and results in a reduction of body fat, but it’s not that simple, it’ll also break down stored sugar (glycogen), and if you create a large enough deficit or stay in a deficit for too long, it’ll start breaking down muscle too.
You’ll often see trainers put clients into a sever caloric restriction and then opt for the go-to for fat burning – HIIT. But is HIIT really all that simple? push yourself for 20-30mins a day and watch the felt melt off? Could happen, but most people who do this style of training for quick fat last tend to be overweight and previously inactive, so how can a trainer tell you your weight loss is from fat and not another source? (no, body fat scales are not accurate, they are a rough estimation based off weight, height and age).
This isn’t to say HIIT will NOT make you lose weight, anyone in a deficit and increased energy expenditure will lose weight eventually. But consider the following:
High-intensity training while in a low carbohydrate-driven caloric deficit increases inflammation levels. Several studies, including one done in 2012, show that training in a glycogen-depleted state drives up levels of proinflammatory proteins higher than normal. This reflects that it’s much more stressful to perform high-intensity exercise, which is very energy demanding, when the body’s glycogen stockpiles are running low.
Chronically elevated cortisol levels lead to glucocorticoid receptor resistance, which further increases inflammation. Most people are aware that cortisol can prime fat cells around the abdomen for fat storage, but what most people forget is that it’s also a potent anti-inflammatory hormone. Recent research shows that during periods of chronic stress, cortisol-binding receptors (known as glucocorticoid receptors) can get burned out. This means that: A.) cortisol becomes less effective at turning off inflammation, and B.) cortisol levels become chronically elevated.
Inflammation decreases insulin sensitivity. While chronically high levels of inflammation can have a wide range of negative effects, one of the most important for fitness and body composition is the connection between inflammation and insulin sensitivity. Several papers have shown that inflammation can lead to insulin resistance in a variety of tissues, from muscle to fat, the liver, and even the brain.
Leptin resistance interacts with dopamine to influence the reward for eating. More and more research shows that leptin (a hormone produced in fat cells involved in signaling the brain to stop eating) interacts with dopamine to influence our behaviors, specifically our drive to eat. In short, leptin resistance can change our reward-driven dopamine circuitry so it takes more and more food to feel the same level of satiety from eating.
The final section sums up a lot, people are horrendously bad at gauging how much work they’ve actually done. Made worse by following FitBits and other activity trackers. Activity trackers can be useful, but again they are an estimation. On my facebook and Instagram I see lots of photos of “wow what a workout – 700 cals burnt”….Here’s the issue, your metabolism isn’t constant, despite having a heart rate of 150 for say 45 mins which roughly equates to about 400-500 cals, you’re metabolism constantly adjusts during high levels of exertion. In fact, there are hundreds of studies that show that your metabolism is capped. No matter how active we are, it turns out that our metabolism is ultimately limited in the amount of energy it can produce and thus the amount of calories we end up burning.
If you’re interested in reading about it, here’s a good place to start: Increases in Physical Activity Result in Diminishing Increments in Daily Energy Expenditure in Mice
As I said above, we’re very bad at gauging how much work we’ve done and we’re equally as bad at rewarding ourselves for it. This is another great piece of research:
“16 men and women with normal body weights were asked to perform a short, low-intensity workout. After the workout, the participants were asked to estimate how many calories they had just burned. They were then taken to a buffet and told to do their best to eat the equivalent number of calories they believed they burned in the workout.
In other words, if they thought they had burned 300 calories during their workout, their goal at the buffet was to eat 300 calories to refuel. The researchers wanted to find out how accurately people could gauge their energy expenditure and subsequent intake after exercise.
The results, summarized in the chart below, are nothing short of eye-opening.
The “calories estimated” bar shows that participants believed their workout burned 800 calories. The reality: they only burned 200.
At the same time, when taken to the buffet, the participants ate close to 600 calories. This was roughly 3 times the number of calories they had actually burned in the workout!
“CONCLUSION: These results suggest that normal weight individuals overestimate EE[energy expenditure] during exercise by 3-4 folds. Further, when asked to precisely compensate for exercise EE with food intake, the resulting energy intake is still 2 to 3 folds greater than the measured EE of exercise.”
What can we take from this study? We tend to eat more than we’re aware of. This is mainly due to the fact our brains are biologically hardwired to fight back when a lot of energy is expended through activity and life stress and not enough is coming in from food. It is a good explanation as to why so many people go all out in the gym for a few weeks, just to fall out the wagon and return to binge eating and weight gain. This process tends to repeat where they go to the gym and use the workout as a challenge to burn as many calories as they can. The more calories they burn, the more fat they’ll lose…or so they believe. They take pride in eating fewer and fewer carbs and making sure their foods are low fat. Eventually a bad day leads to a binge reward stimulation, and they’re back to square one.
In a recent poll, a staggering 75% of the UK deemed themselves to be eating healthy, yet 1/3rd of the country is obese and another 1/3rd is overweight. People might be eating healthier foods, but they’re still eating too much of them. 90 cal popcorn treat, followed by the 100cal cookie treat and then finally the 280 cal protein bar treat. Then, despite this, it’s the “cheat meals” at the weekend, then it’s a “cheat day” which turn into cheat weekends and we’ll start again on Monday….When not used correctly, these refeeds sabotage any progress made during the week.
this blog is based on the work of Joel Jamison from https://www.8weeksout.com/....give it a look over if your interested!
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