Myth: Eating at Night Will Make You Fat.

December 7, 2017,

Rebecca Haresign

Many people think eating before bed will result in weight gain, but is there any truth behind this? We reviewed the scientific research looking at the effects of a late-night snack and whether it can help or hinder you in reaching your goals.

What foods tend to be eaten in the evening?

The problem many people face is the type of foods eaten in the evening tend to be high in calories and lower in positive nutrients such as fibre, protein, vitamins and minerals. These calories also often aren’t accounted for in a daily calorie target and can lead a person to consuming more calories than they need. If a person is regularly overconsuming calories this can lead to weight gain over time.

Good nutrition before bed

Many of us try to limit energy intake in the late evening, particularly when trying to lose weight. This is likely to be driven by articles suggesting that metabolism slows down during sleep, and therefore consuming calories in the evening may promote energy storage. However, research has also shown that a higher protein intake throughout the day can reduce the typical drop in sleep-time metabolism compared with the intake of diets high in carbohydrate and fat (1).

Research carried out by scientists in the USA published in the British Journal of Nutrition has also shown possible benefits to consuming whey protein before going to bed to support both weight loss and muscle building goals (2, 3).

How can this help to support weight loss?

One of the studies investigated the effect of night-time protein intake on appetite in sedentary overweight women. The researchers found that when a whey protein drink was consumed at night before going to bed participants felt more full the following morning, and had a reduced desire to eat compared to consuming other types of protein, or a placebo (3).

One interpretation of this study is that consuming a whey protein drink before bed can help to keep you feeling full through the night and into the following morning. This may help a person to control their overall calorie intake and, over time, could help with weight loss.

Researchers have shown that consuming a serving of protein that provides 140-150 calories half an hour before sleep can have a more favourable effect on resting metabolism the following morning compared with not consuming anything (2).

Resting metabolism, also known as basal metabolic rate (BMR), is the amount of energy your body burns when it is at complete rest. The more calories you’re burning from basic tasks such as breathing or moving all contribute to your total daily energy expenditure, so the total number of calories you’re burning each day.

How can this help to support muscle building?

Researchers investigating night-time consumption of protein and morning resting energy expenditure in active men found that consuming 140-150 calories of a whey protein drink before bed can improve V02 max (maximal oxygen consumption) and resting energy expenditure the following morning compared to going to bed on an empty stomach. Researchers also found this type of drink to be more satiating than consuming other types of protein or carbohydrates (4). This finding is relevant to individuals who are physically active and may also be relevant to individuals trying to lose or maintain their body weight.

Whilst these findings contradict the popular belief that energy intake should be limited in the evening, protein consumption before sleep after an evening resistance training session can increase muscle protein synthesis overnight (4).

How can you include whey protein before bed?

You may be asking yourself how you can incorporate this into your current Isagenix system. The good news is that all you’ll need to get started is a canister of IsaPro®. With 100 calories and 18g of undenatured whey protein per scoop, you’ll need to mix between 1-2 scoops with water, blend with ice if you wish, and consume last thing before going to bed. Whilst this isn’t approved for use on Cleanse Days*, this can be included on your Shake Day schedule.

This is a relatively new area of research and there are few long-term studies to show conclusive evidence, however in the meantime we can enjoy IsaPro before bed knowing that, at the very least, we’re reaping the many benefits that whey protein can offer.

* A Cleanse Day is a nutritionally supported fast that nourishes and energizes your body’s own detoxification systems. For further Cleanse Day information, visit


  1. Whitehead JM, McNeill G, Smith JS. The effect of protein intake on 24-h energy expenditure during energy restriction. Int J Obes Relat Metab Disord 1996 Aug;20(8):727-32
  2. Madzima TA, Panton LB, Fretti SK, Kinsey AW, Ormsbee MJ. Night-time consumption of protein or carbohydrate results in increased moring resting energy expenditure in active college-aged men. Brit J Nutr 2014;111:71-77
  3. Kinsey AW, Eddy WR, Madzime TA, Panton LB, Arciero PJ, Kim J, Ormsbee MJ. Influence of night-time protein and carbohydrate intake on appetite and cardiometabolic risk in sedentary overweight and obese women. Brit J Nutr 2014;112:320-327
  4. Res PT, Groen B, Pennings B, Beelen M, Wallis GA, Gijsen AP, Senden JM, VAN Loon LJ. Protein ingestion before sleep improves postexercise overnight recovery. Med Sci Sports Exerc 2012 Aug;44(8):1560-9

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