Part 2: Warning: Dieting Will Take You To A Dark Side
In Part 1 I claimed that most diets don’t work – shocking right?
But should diets actually come with a health warning?
Perhaps…
You see as dieting has become normalised many people innocently embark on them without any knowledge or understanding of the potential risks and the darker side effects.
For example, you may be surprised to discover that scientific evidence exists which PROVES there are biologically predictable, counterproductive results of dieting.
That’s because dieting causes the body’s ‘ innate survival’ and ‘ starvation response’ to kick in. This is an instinctive, hard- wired physical and psychological mechanism that causes the body’s metabolism to slow down. In addition, restrictive eating leads to an array of physical, psychological, emotional and behavioural negative side effects.
But what’s really thought provoking is these effects were understood over nine decades ago as a result of some very interesting wartime studies that revealed the effects of restrictive eating.
Let’s start by exploring these studies in detail…
Wartime experiments with modern day implications
Food shortages and mass starvation were rife at the end of the two World Wars in Europe.
This led to a series of scientific experiments designed to determine the effect on healthy people of a restricted diet – and the results are something I believe every dieter should be made aware of.
In both experiments all the participants were mentally, physically and emotionally healthy. What’s more, they had none of today’s pressure to look a certain way.
Study 1: Human Vitality and Efficiency Under A Prolonged Restricted Diet - 1918
This first study carried out by the University of Massachusetts in the winter of 1917- 1918 aimed to discover how low metabolic rate could go before intellectual and physical activities became impaired.
26 healthy young men were put on a restrictive diet to quickly lower their body weight by 10%. This weight was sustained for a few months during which time their physical and psychological functions were carefully monitored and documented.
Study 2: The Biology of Human Starvation - 1950
This year long study led by Ancel Keys (a physiologist at the University of Minnesota) documented the effects of a restricted diet on 36 male subjects, drawn from 100 men who had volunteered for the experiment as an alternative to military service.
These experiments intentionally created a situation whereby subjects lost weight by restricting food.
(Notice -this is the same premise that underlies modern day fad diets – i.e. reduce your calorific / food intake and you’ll lose weight).
At the start of both studies it was widely expected that restricted eating would lead to a lowered metabolic rate.
BUT the men also experienced a series of other side effects that were NOT anticipated. Check them out below…
Observed physical effects:
1. Impeded temperature regulation: As the men’s metabolic rate slowed, they complained of feeling cold.
2. Sleep disturbances: Despite feeling tired they struggled to get a goodnight’s rest.
3. Vision: Aching eyes, seeing spots and unable to focus properly.
4. Hearing: Ringing in the ears.
5. Heart Problems: Shrinking heart muscle and volume caused some of the men to suffer irregular heartbeat and arrhythmia.
6. Lowered Blood Pressure: On rising they felt giddy and some had momentary blackouts.
7. Digestive problems: Bloating, stomach ache, diarrhoea and constipation were common.
8. Impaired mental function: Many had difficulty concentrating, found their judgement and comprehension suffered and became easily distracted from their studies.
9. Sexual function: They soon lost all interest in sex.
10. Accelerated aging: Their skin dried and their hair began thinning or fell out.
11. Physical strength: As their weight dropped the men lost their endurance for walking long distances, standing for long periods, carrying, lifting and climbing stairs. They generally felt lethargic. Their muscles wasted as their weight reduced and they frequently cramped or felt sore, tingled or prickled.
Observed behavioural effects:
1. Loss of perspective: Before long the men’s obsession with food, hunger and weight loss eclipsed all other interests. They began obsessively hoarding and swapping recipes and even replaced pictures of their wives and girlfriends with pictures of food.
2. Food cravings: Men were reportedly found rooting around in dustbins for food.
3. Altered eating habits: Mealtimes would last as long as two hours to savour and prolong the experience of eating.
4. Binge eating: In the 1917 experiment, volunteers could eat freely at Sunday lunch once a fortnight. Despite being cautioned to eat moderately, all participants ate excessively and uncontrollably - often consuming in excess of 5000+ calories.
5. Purging habits: After bingeing, the men felt an overwhelming desire to counteract their indulgence. This usually resulted in excessive exercise or restrictive eating in the following days.
Observed emotional and psychological effects:
1. Emotional shifts: These psychologically strong men reported feeling moody and depressed, nervous and anxious, irritable, apathetic and social y withdrawn.
2. Distorted body image: Despite being thin, many of the men began complaining of feeling overweight.
N.B: The reasons for these emotional responses are now known. You see a restrictive diet can have a profound impact on the level of hormones responsible for regulating mood and combatting depressive thoughts and anxiety.
A study reported in “Tryptophan, Serotonin and Melatonin, Basic Aspects & Application” (1999) found that healthy women going on a 3- week moderate weight loss diet of 1000 calories experienced lower plasma concentrations of “the 5- HT precursor, L- tryptophan (TP)” (a chemical known to regulate mood) along with “consequent increases in hunger and loss of satiety”.
Problems with recovery…
Once the experiment finished it took around five months for the men to stabilise their weight and resume normal eating habits. This “return to normality” occurred when the body reached “set point” – an optimal weight for a person’s size and level of activity.
But in the meantime, once food was no longer restricted, many of the volunteers ate more or less continuously. And interestingly, they still complained of feeling hungry after large meals. It means that most of the men initially experienced substantial weight gain. And this was often coupled with a higher percentage of body fat (up to 40%).
So how are these studies relevant for today’s modern dieters?
If you’ve ever been on a diet perhaps you too can recall experiencing some of these side effects. Perhaps you felt physically different or emotionally more unbalanced. Maybe you found yourself obsessing over food and continuously thinking about your next meal. Perhaps you binge ate and if your diet failed or you stopped dieting, maybe you gained weight.
Perhaps you felt these dietary results were your fault and that you simply didn’t have the staying power and motivation to see the diet plan through.
But is that the truth?
Given the results of these scientific studies it seems there’s something else going on. And I’l reveal what that is in Part 3…