You’ve tried every diet. You succeed at first and see progress, but then somewhere along the way it stops working. At that point, usually, 1 of 2 things happens:
- You slash calories even more, or start working out more, and may see a bit more progress, but eventually it stalls out again. And no matter what you do, you can’t get anything to budge anymore. You may even start to see weight come back on!
- You give up and say screw it, this isn’t working anymore and revert back to old habits. Which typically makes the weight come back, and sometimes with interest.
Honestly, you may even be doing everything right and STILL see weight loss plateaus.
But why? What is happening and what can we do about it??
The Body’s Response to Calorie Deficits and Weight Loss
For us to lose weight, we must be in a calorie deficit. People love to argue against it, but research continues to show that a calorie deficit is necessary to see weight loss. Although when we are in a calorie deficit for a prolonged period of time (8-12 weeks), and weight loss typically occurs, there are responses that the body will begin to have.
These responses often make it harder for us to continue to see weight loss and body-composition changes, and they even make it hard for us to maintain our weight loss!
HORMONAL RESPONSE
There are a few main hormones that play roles in the regulation of our metabolism, body-composition, and our body’s ability to burn fat. These each get impacted by a caloric deficit and weight loss in certain ways that can start to slow down progress. These are by no means the only hormones that get impacted, but these are some of the most notable ones:
- Thyroid Gland Hormones - Your thyroid is host to a number of different hormones, one being triiodothyronine (T3), which is known to play an important role in regulating metabolic rate. When your thyroid is properly supported with enough calories and carbohydrates, it will show increases in circulating thyroid hormones, which often means an increase in metabolic rate. Whereas lower levels of intake or restriction have shown lowered thyroid levels which result in decreased overall metabolic rate [1]
- Leptin - This is your ‘satiety’ hormone, which regulates fat storage and how many calories you eat/burn. Caloric restriction and lower body-fat levels are shown to decrease the amount of leptin produced (meaning we don’t get as full as easily!) [2]
- Testosterone - This hormone is primarily known for its role in increasing and maintaining muscle mass, which helps to increase resting metabolic rate. Testosterone has also shown links in fat-tissue regulation. Research suggests that high testosterone may subdue adipogenesis (your body’s ability to form fat-cells). In a calorie deficit, testosterone decreases, which then in turn may correlate with higher fat storage [3]. Low testosterone can also impact your libido and we often see a drop in sex drive with sustained calorie restriction.
- Cortisol - Cortisol is our stress hormone, and a calorie deficit is an additional stress on the body because we are not supplying the body with adequate energy to function optimally. When energy is restricted (i.e. calorie deficit), research shows that cortisol will rise. [4] This rise in cortisol has shown to impact macronutrient metabolism and actually start to break down muscle mass instead of fat. [5]
In summary, when we stay in a caloric deficit for too long, it shows up to the body as energy being unavailable because we aren’t feeding it enough! Dieting causes increased hunger levels, a slowing of our metabolic rate, and a threat to our muscle mass. This is why dieting gets so hard after a while and it cannot last forever!
METABOLIC RESPONSE
As mentioned above, the impact to our hormones, in turn, impacts our metabolic rate negatively and makes it harder to lose weight in the long-term. There are other functions that also impact metabolic rate when in a calorie deficit.
BMR - BMR is your basal metabolic rate, or how many calories your body burns in a day at rest (to keep your brain functioning, heart pumping blood, etc.). When you lose weight, you are losing either fat tissue, muscle tissue, or both. These are both forms of metabolically active tissue, meaning they burn calories at rest. So as we lose weight, we are losing total calories burned in a day as well. [6]
NEAT - Non-exercise activity thermogenesis refers to how much we move in a day aside from exercise. Our fidgeting, how many steps we walk in a day, chewing food, standing, etc. It has been shown that when you are in a calorie deficit, NEAT naturally decreases subconsciously as a way for your body to conserve energy [7].
TEF - The thermic effect of food refers to the amount of energy it takes the body to break down, digest, and absorb nutrients from our food. It is estimated that about 10% of our total daily energy expenditure, or how many calories we burn in a day, comes from the thermic effects of food [8]. So as we eat less calories in an attempt to lose weight, we also see a decrease in the thermic effect total burn of calories as there is less food to breakdown.
MENTAL/EMOTIONAL RESPONSE
All of us that have gone through a diet or calorie restriction can attest to the fact that it is HARD. You are tempted, it takes more effort, you find yourself moody, you often feel pity towards yourself, or guilt if you ‘cheat’ on the diet. Overall, it is simply draining emotionally, physically, and mentally. This is why whenever we put clients into a ‘cut’ to create weight loss, we always make sure they are mentally prepared and in a low-stress time in their life.
This can be demonstrated with the observations around the 1944 Minnesota Starvation Experiment, where clients were put in an extreme caloric deficit to study the physical and psychological effects of prolonged, famine-like starvation on healthy men, and the post-starvation period rehabilitation. They wanted to see the impact of concentration camp like conditions.
It should be noted that this study is now seen as extremely unethical and would never be re-created.
But the findings have served important to paving the way in the understanding around impacts of eating disorders. The study showed that the majority of the research subjects experienced periods of severe emotional distress and depression. They reported a decline in concentration and judgmental capabilities.[9]
Although the caloric deficit was on an extreme level with the Minnesota Experiment, we can see similar impacts with more moderate deficits as well. We often see calorie cuts result in mood swings, tiredness, more impulsive behaviors, and other emotional and mental responses.
When To Take a Break From Dieting
We get it, we know that you have goals and want to look better and feel better, but sometimes our body has other plans. These are some ‘bio-feedback’ markers to watch out for if you’ve been in a long-term calorie deficit that our body uses as a way to tell us to give it a break from energy restriction and it needs more calories:
- Bowel movements have slowed down in frequency and/or constipation is happening often.
- Sleep quality has decreased.
- Hunger levels are increasing.
- Performance in gym has severely declined and/or injuries are starting to occur more frequently. These are both signs your body is under-recovering.
- Mood swings are becoming more frequent.
- The scale is no longer moving and you may actually be seeing weight gain, even with adherence.
- You’re noticing more extreme fatigue/tiredness and lacking energy throughout your day.
- Sex drive has decreased.
- Females: Periods have become irregular or stopped altogether.
- You’re getting sick more often.
There are many other biofeedback markers that may show up as well, but this is a great list to keep in mind.
How to Take a Break from Dieting
So you’ve realized that it may be time for a break from the calorie deficit you’ve been at, but now what?
How do you take a break without regaining all of the weight back?
How do you improve your hormone function again, or bring your metabolic rate back up?
What if you aren’t at your ‘goal’ yet??
Let’s be honest, after a strict diet, we WANT more food, and we are also in FEAR of more food at the same time. If you’re going from a state of restriction and don’t want to see all of the weight come back on, we need to be careful of how we reintroduce calories.
This is where Reverse Dieting comes in…
A tactical way of slowly (or quickly) increasing calories back to a ‘maintenance’ and healthy level for your body to restore proper hormonal and metabolic functioning again.
If you want to find out how Reverse Dieting works and how it can work for you, tune in next week for the next blog where we will break it all down!
REFERENCES
[1] - Kim B: Thyroid hormone as a determinant of energy expenditure and the basal metabolic rate. Thyroid. 2008, 18: 141-144. 10.1089/thy.2007.0266.
[2] Strohacker K, McCaffery JM, Maclean PS, Wing RR: Adaptations of leptin, ghrelin or insulin during weight loss as predictors of weight regain: a review of current literature. Int J Obes. 2013, 1-9.
[3] De Maddalena C, Vodo S, Petroni A, Aloisi AM: Impact of testosterone on body fat composition. J Cell Physiol. 2012, 227: 3744-3748. 10.1002/jcp.24096.
[4]Rossow LM, Fukuda DH, Fahs CA, Loenneke JP, Stout JR: Natural bodybuilding competition preparation and recovery: a 12-month case study. Int J Sports Physiol Perform. 2013, 8: 582-592.
[5]Rooyackers OE, Nair KS: Hormonal regulation of human muscle protein metabolism. Annu Rev Nutr. 1997, 17: 457-485. 10.1146/annurev.nutr.17.1.457.
[6]Leibel RL, Rosenbaum M, Hirsch J: Changes in energy expenditure resulting from altered body weight. N Engl J Med. 1995, 332: 621-628. 10.1056/NEJM199503093321001.
[7] Weigle DS, Brunzell JD: Assessment of energy expenditure in ambulatory reduced-obese subjects by the techniques of weight stabilization and exogenous weight replacement. Int J Obes. 1990, 14 (Suppl 1): 69-77. discussion 77–81.
[8] Tappy L: Thermic effect of food and sympathetic nervous system activity in humans. Reprod Nutr Dev. 1996, 36: 391-397. 10.1051/rnd:19960405.
[9] Tucker, Todd (2006). The Great Starvation Experiment: Ancel Keys and the Men Who Starved for Science. New York: Free Press. ISBN 0-7432-7030-4.
