We all want something for nothing, or the case of weight loss: results with little effort. Often articles on the internet promise this, but fail to deliver. Why? Because they fail to tackle the root of the problem. First, we need to understand what drives us to we eat, and why we make poor food choices. Then, we can devise strategies to correct this.
What drives us to eat?
For the vast majority of our evolution we were hunter-gatherers living in small tribes. In that environment calories were scarce. We had to hunt animals or gather plants to eat. Both these activities took considerable effort and would be the main activities of the day. However, we also had to decide which animals and plants to obtain.
We did this by choosing the plants and animals that gave us the most calories, for the least effort. Imagine if you spent all day chasing a little squirrel, you could burn more calories than you get from the meat. That is not an effective strategy. In contrast, imagine a group of hunters hunting a big elephant, much more calories per unit of effort there. This is called Optimal Foraging Theory and found across the animal kingdom. Homosapians (aka humans) are also animals and have therefore evolved the same strategy for food searching.
The high-calorie diet of the Ache tribe
The Ache are a well studied hunter-gatherer group and are an excellent example of optimal foraging theory in practice. They live in the subtropical forests of Paraguay, and focus on gathering high-calorie foods such as meat, honey, fruit, and palm starch . They don’t spend all day collecting spinach and broccoli.
The Ache tribe demonstrate our hardwired desire for high-calorie foods. Furthermore, the Ache had no concept of moderation and would engage in eating feats worthy of awards. For instance:
‘[researchers] observed among the Ache – men eating five pounds of fatty meat each in one sitting, drinking one and a half litres of pure honey or eating thirty wild oranges.’ 
Food choices in the modern world
Consequently, we can see that human beings are wired to gorge on high calorie food. However, in the modern world this poses a problem. Unlike the Ache we have near unlimited access to calorie-dense foods and could eat all day long. When mice are given unlimited access to junk foods, they increase their calorie intake by 30% and are soon obese . However, we have the ability to exercise restraint. We do this by making choices, in much the same way as the Ache do. We have to decide if the benefits of eating something outweigh the costs.
The benefit of eating a donut is the sweet taste, and the immediate pleasure that it gives us. The costs are the monetary price of the donut, and the possible weight gain in the future. You may rationally value the long-term benefit of staying slim, over the short term pleasure of eating. So why do you choose the donut, even though you know you shouldn’t? Well, the answer lies in how our brains make decisions.
Why do we choose the donut?
In behavioural economics, there is a well-known bias that humans exhibit when making decisions, called time inconsistency . It states that when making a decision, we value our current selves more than we value our future selves. We choose the pleasure of the donut because there is an immediate benefit for us, and we let our future selves deal with the cost of weight gain. The short-term loss is the monetary cost of the donut, which is negligible for most people.
A great example of this was in an experiment conducted in 1999 concerning film choice . Researchers gave participants the choice of several films to rent, the subjects had to pick one to watch immediately, another to watch in two days, and another to watch after four days. People overwhelming choose ‘low-brow’ films to watch immediately such as Mrs. Doubtfire, and ‘high-brow’ films to watch later like Schindler’s List. This showed that the subjects preferred the immediate thrill of low-brow movies, and did not want to have to dissect the meaning of more complex films. However, when planning for the future they choose the high-brow movies, because overall they knew they were the better choice.
It makes sense that we have evolved to make decisions based on the short-term effects, since during our time as hunter-gatherers we needed to make immediate gains such as acquiring calories. The childhood and adulthood mortality rates are much higher in hunter-gatherers societies than in the modern world. Tribal warfare, hunting injuries, and infectious diseases, made the future uncertain. Those who prioritised the short-term were more likely to survive and pass on their genes.
Weight loss tip 1: Increase effort
The first strategy you can use is to increase the short-term costs of eating food. We do most our eating at home and work. Therefore, reduce or eliminate high calorie snack foods in these environments. This increases the effort required, as you would have to go to the nearest shop to get them.
In one famous experiment, researchers put chocolates either on top of workers’ desks, inside a drawer in their desks, or on a shelf two meters away. Those workers with the chocolates on top of their desk ate 2.9 more than those with them in a drawer, and 5.6 more than those with them on the shelf .
Ideally, you should have to cook or prepare all the food in your home. By doing this, you will have increased the effort required to eat, and this will pretty much eliminate any snacking. For example, you can have oats, instead of oatcakes. An oatcake you can easily pick up and snack on, whereas you would have to cook the oatmeal. Also, you could stock your home and work environment with low-calorie snack foods such as fresh fruit or salad vegetables, like carrot sticks.
Weight loss tip 2: Decrease food decisions
The second weight loss strategy you can use is to reduce the number of food decisions you need to make. We need to make a decision every time we encounter a food cue. Food cues can be internal such as hunger, or external such as food advertising. We can easily reduce external food cues, whereas internal food cues are more complex.
Firstly, limit your exposure to food cues such as reducing the amount of visible food in your home and workplace. Also, reduce your exposure to food cues on TV such as adverts and cooking shows. One experiment showed children exposed to food advertising increased snacking by 45%, and adults also increased their food intake .
Secondly, supermarkets and shops are great at using food cues to get you to buy more. Beware of the snack aisles placed by the checkouts. Also, if you shop for a few days at once you will have fewer decisions to make overall and will make better choices. Scientists view willpower as a muscle that becomes fatigued. The more decisions you have to make the lower your willpower becomes, this is known as the theory of ego depletion or decision fatigue . For example, Barack Obama explained when he was president:
‘You’ll see I wear only gray or blue suits… I’m trying to pare down decisions. I don’t want to make decisions about what I’m eating or wearing. Because I have too many other decisions to make.’
Lastly, never go shopping hungry. Research has shown that hungry shoppers buy the same number of foods as satiated shoppers, but more calories . Meaning, they buy high-calorie junk foods, instead of low-calorie healthy foods.
- Calories were scarce during our time as hunter-gatherers, therefore we evolved to search for them in the most efficient manner.
- Optimal foraging theory states that we seek the most calories for the least effort.
- In the modern world we have to weigh the benefits of eating food against the costs.
- The time inconsistency bias states that we value immediate gains (the pleasure of eating), more than long term losses (weight gain). Therefore, we often choose junk food, even though we ‘know’ we should not.
- Increase the short-term costs of eating food to reduce snacking. For instance, if you have no junk food in the house, you would have to go to the nearest shop to get it.
- Decrease the number of food decisions you have to make by reducing your exposure to food cues. Food cues include food adverts, snack counters, and visible food at home.
- Don’t go shopping when hungry and beware of decision fatigue.
2. Guyenet, S.J. (2017) ‘The Hungry Brain: Outsmarting the Instincts that Make us Overeat’, Penguin Random House UK: London.