satiety

First, what is satiety?

Satiety is the feeling of fullness and the suppression of hunger for a period after you eat and can influence how much or how soon you next eat. The two primary hormones that affect our appetite would be the hunger hormone known as ghrelin and the satiety hormone called leptin. Both hormones have opposing jobs. Ghrelin gets secreted by the digestive tract when your stomach is empty, this motivates you to eat, when the stomach starts to stretch and, nutrients get absorbed, secretion begins to slow down and eventually stop.

Leptin is known as the satiety hormone or master hormone due to its influence on energy balance (and other metabolic housekeeping). It does this by sending signals from your fat cells to your brain that you have enough energy and therefore decreases the motivation to eat. Low levels of leptin tell the brain that fat stores are small and thus elevates our motivation to eat.

So, if you’re trying to lose weight, eating highly satiating foods (those that keep ghrelin low and leptin high) is a great way to help you stay on track. The longer you suppress your hunger, the more likely you can go longer without food and potentially eat less at your next meal. If, though you don’t feel very satiated after a meal then there is a high chance you will make unfavourable choices like snacking more on calorie dense foods such as cakes, biscuits, and sweets. This can then lead to you overeating and potentially gaining weight.

What are the main players when trying to increase your satiety?

1. A High Protein Diet

Numerous studies have observed that the macronutrient protein has the most significant satiating effect over fat and carbohydrates. A study done by Lejeune et al (2006) looked to investigate 24hr satiety, related hormones, energy and substrate metabolism during a high-protein (HP) diet in a respiration chamber.

They concluded that: “An HP diet, compared with an adequate protein (AP) diet, fed at energy balance for 4 d increased 24-h satiety, thermogenesis, sleeping metabolic rate, protein balance, and fat oxidation. Satiety was related to protein intake, and incidentally to ghrelin and GLP-1 concentrations, only during the HP diet”.

2. Satiety Index of Common Foods

Not only just protein-containing foods affect your satiety; the composition of the food can have an impact. In 1995 research published in the European Journal of Clinical Nutrition by Holt et al. that looked at what best foods worked for reducing appetite. The researchers tested 38 different foods for the same amount of energy (240 kcals) separated into six different food categories (fruits, bakery products, snack foods, carbohydrate-rich foods, protein-rich foods, breakfast cereals) by feeding them to groups of 11-13 subjects.

They concluded: “The results show that isoenergetic (equal amount of calories) servings of different foods differ greatly in their satiating capacities. This is relevant to the treatment and prevention of overweight and obesity”.

They found that boiled potatoes ranked the highest and croissants ranked the lowest for reducing hunger and controlling appetite.

I have created a chart (below) of the top 15 foods along with the percentage score compared to bread (100%) to show it more clearly.

As you can see on the chart, foods that hold a lot of water and contain a substantial amount of fibre (fruit, wholemeal, starchy carbs) rate high on the satiety index.

Despite this though people often still eat when they feel satiated. Many other factors influence eating behaviour as well as the body’s satiety signals, such as:

• The hyper palatability of the food and drink (i.e. how much pleasure is experienced during consumption)
• The variety of food and beverages available.
• The social situation around eating occasions (e.g. birthdays, Christmas time etc.)
• Our environmental surroundings (e.g. food available to us close by)
• Our emotional state.
• Portion sizes.
• Impaired decision making (e.g. alcohol consumption)

This is the main reason why you struggle to finish your Christmas dinner, but you have no problem finishing your dessert. On your dinner plate you probably have your turkey, ham, potatoes and veg like those tasty Brussels sprouts (say what?) all ingredients that are very satiating. Then after a few hours when you are not feeling like a busted sofa you are straight away wondering what to have for dessert. You fill your bowl to the throat with ice cream, custard, apple tart, you name it, and yet you can quickly go up for seconds or possibly thirds like me.

John’s Tips:

• Include a protein source at each meal. Foods high in protein include meats, such as chicken, lean beef, whey, eggs and pulses.
• Foods that have water added when cooking, such as soups and porridge also seem to aid in satiety.
• Foods that are high in fibre also enhance the feeling of satiety so try and include high fibre foods in the diet such as wholegrain products (bread, oats, brown rice etc.) pulses (baked beans, red kidney beans, lentils, chickpeas etc.) fruit and vegetables
• Chewing your food more slowly and often may also help with satiety.
• Don’t drink your calories. For example, eating an apple rather than drinking apple juice will promote more satiety.
• Drinking a glass of water before and during meals seems to reduce appetite.

Resources:

https://academic.oup.com/ajcn/article/83/1/89/4649634?searchresult=1

https://www.ncbi.nlm.nih.gov/pubmed/7498104