1
F ood craving is usually described as a strong motiva- tion or intense desire or urge to eat a specific food. Often, craving is also referred to as an urge to eat something even when there is no metabolic need. It is inter- esting to note that many of the foods frequently craved are high in carbohy- drate and fats and mostly foods which are processed. Food cravings have often been associated with high body mass index (BMI) and associated con- ditions which are predominant risk factors for non-communicable dis- eases. Therefore, there is a surge in the interest to explore the nutritional and health impacts of food cravings. Are food cravings really a malfunc- tion or a menace? What’s the mystery behind them? WHAT CAUSES FOOD CRAVINGS? The true picture of food craving is complex and there are numerous theo- ries about it. The underlying causes of craving may be multiple — including psychological, conditioning, emotion- al, sensory and food imaging, to name a few. One of the most researched fac- tors as a possible trigger for food crav- ings is ‘mood’. Depressed and stressed individuals or sleep deprived individ- uals can also suffer cravings and end up in binge eating. The addiction literature focused con- siderable attention on the relation- ship between cravings and the expo- sure to a variety of external cues, such as the sight and thought of foods (like sweets, snacks, alcohol). Cravings have also been depicted as seasonal affective disorders, as some people experience increased cravings for sweet carbohydrate and fat-rich foods as winter approaches. As is known our gut has a varied species of microbes. These microbes are constantly under selective pres- sure to increase their fitness and research suggests they could be manipulating the host eating behav- iour. Microbes could constantly look for foods that they need to thrive on or could demand the foods that suppress their competitors. These activities of microbes could end up prompting the host individuals to opt for certain foods or even crave them. For instance, sugar/sweet craving can increase with inflammation promot- ing gut bacteria, which are unhealthy. In contrast, National Institute of Nutrition studies have shown that high fat diets and high carbohydrate diets alter gut microbiota which may have an effect on neuro transmitters that could in turn affect cognition and mood. How this can help prevent crav- ing is yet to be established. ARE THE CRAVINGS FOR SAME FOODS CAUSED BY SAME FACTORS? Craving the same food could have dif- ferent mechanisms in different indi- viduals and at different times. Craving a particular food, say potato wafers, could be caused by the percep- tion that these are often depicted as forbidden foods (unhealthy/junk foods). Attempts to restrain their eat- ing could trigger increased food crav- ings. Studies also show that diet composi- tion and macronutrient intake regula- tion also play a role in craving sweet- tasting, palatable foods. It has also been observed by some researchers that preference for a particular macronutrient is influenced by the prior macronutrient composition of the diet. If a specific appetite for a par- ticular macronutrient does exist then removing that macronutrient from the diet should cause a selective sub- sequent increase in the consumption of, and possibly in susceptible individ- uals’ “craving” foods that are rich in that macronutrient. CAN CRAVING BE MEASURED? Scientists around the globe have tried out many behavioural methods to measure craving, the most common approach appears to be self-reporting of participants about their craving a pre-determined list of foods. Studies show that the highly craved foods are categorised into four types — high-fat foods, sweets, starchy carbohydrate foods (like noodles, potato chips) and fast-foods. WHAT IS IT IN INDIA? There are hardly any systematic sci- entific studies. The Indian economic and epidemiologic transition is reflected in the dietary habits of Indians, where a shift from home- made nutritious foods to easily acces- sible and palatable processed food is visible. Increasing dietary diversity is the current priority for Indians, and currently high amounts of starch, fat and little amounts of fibre and protein are consumed across all age and gen- der groups. The consumption of monotonous diets has also been asso- ciated with craving carbohydrate and fat rich foods. In addition, marketing foods online with attractive discounts makes indi- viduals to crave more. It is an interest- ing observation that cravings for car- bohydrate and fat rich foods does not occur during regular mealtimes; instead, they primarily occur during snack time. It has also been seen that nocturnal sleep is associated with increased food cravings and thereby making the BPO and shift employees the most affected and vulnerable seg- ments of the population. STRATEGIES TO REDUCE FOOD CRAVINGS - DO THEY WORK? To date, a handful of studies have focused on strategies to reduce food cravings. Studies have generally shown that craving-reduction strate- gies, such as thought suppression (try- ing not to think about the craved food) or cue-exposure response prevention (presenting an individual with the craved food but not allowing them to eat it) are not very successful. Thus there is a need to seek new and different craving reduction techniques. Alternatively, experts and nutritionists sug- gest a number of sim- ple measures that can help keep food cravings at bay. Being physically active, drinking plenty of water, consuming micronutrient and fibre- rich fruits and vegetables as part of daily diet may help curb craving. Other tips include trying to consume healthy, natural and minimally processed foods when in stress, maintaining a balanced diet, main- taining mealtime and following a similar healthy diet pattern daily and small but frequent meals and eating mindfully. (The author is director, National Institute of Nutrition, Hyderabad) F ood cravings are linked to weight gain and attendant ail- ments. The best way to fight cravings is to de-condition ourselves, which is to remove the stimulus that triggers the response, says clinical nutrition and metabolism expert John W. Apolzan in an email inter- view to DC. He is director at Pennington Biomedical Research Centre, Louisiana State University System, USA. Why do we crave high-calorie foods that add to weight gain? All foods can lead to weight gain if consumed to excess. However, more energy-dense foods do tend to lead to weight gain. Further, these items are filled with sugar and fat which are the macronutrients typically craved. Overall, chocolate tends to be the most craved food item. You refer to ‘conditioning response’ to explain food craving. But it’s usual for pregnant women to crave a variety of foods and the popular notion is it may have to do with deficiencies? Yes often with palatable food it is a conditioning response. However, there is likely a different mecha- nism (or mechanisms) at play for those that are malnourished and/or have deficiencies. The conditioning response would not hold true if someone was protein deficient and attempting to over-consume energy to meet their protein needs/require- ments. Have you observed any link to craving in the ambivalence between one desiring a food and wanting to control its intake? Or the craving owes to a dilemma: to eat or not to eat? I am not 100 per cent sure of the ques- tion. Actually energy restriction decreases crav- ings. I think it is important to note that we found it is the frequency of consuming food items versus the amount that was associated with cravings (Obesity 2017). Of course it is natural to want to eat a variety of foods including those that may be less healthy. The key is just to do so in moderation in terms of amount and frequency. Thus like much of life, it is truly about finding a happy, healthy medi- um. Would you say culture and psy- chology play crucial roles in trig- gering specific food cravings? I think culture and psychology play rather large roles in triggering spe- cific food cravings. You’re not going to crave a food you’ve never tasted. Further conditioning likely occurs due to the regions culture and psy- chology. What are best possible ways to tackle craving, especially because a whole lot of lifestyle diseases are linked to reckless eating habits? Decreasing energy intake through lifestyle interventions has been shown to be successful in reducing cravings. Nearly all weight loss diets lead to decreases in food crav- ing. So the first would be weight loss. Secondly with conditioning model of food cravings, one would ‘decondition’ oneself. If someone eats a bowl of ice cream nightly dur- ing a specific TV programme then you would try and get him/her to stop the stimulus (i.e. watching the television programme). Go for a walk, go to the gym and so on. DR HEMALATHA R. PAGE 13 DECCAN CHRONICLE During weight loss treatment, reductions in the frequency of consuming certain foods resulted in decreased cravings for those foods. John W Apolzan and team D C SUNDAY | 2 JUNE 2019 | THIRUVANANTHAPURAM D is C ourse DUMP CRAVINGS Food cravings ruin health because they are triggered by external cues rather than genuine demands of the body. Cultural and psychological factors also aid craving. Again, gut bacteria provoke craving to suit their interests rather than that of the body Mystery, menace or a malfunction ‘You are not going to crave food you never tasted’ One of the most researched factors as a possible trigger for food cravings is mood . Depressed and stressed individuals or sleep deprived individuals can also suffer cravings and end up in binge eating. It is natural to want to eat a variety of foods including those that may be less healthy. The key is just to do so in moderation in terms of amount and frequency JOHN W. APOLZAN CUT YOUR CRAVING Since our environ- ment is full of cues that could tap into our cravings, such as advertising and pho- tos on social media, overcoming them isn’t so straightforward. Research has found that one of the most effective ways to curb cravings is to cut the craved food from our diet, which runs counter to the argu- ment that we crave what we need. THE CUES Dogs drool at the hint of food. Not just that, pets exhibit signs of craving before regular food time. If one always eats popcorn while watching favourite TV show, it’s likely cravings for popcorn will increase whenever one watches it. The afternoon slump is another example of this response in practice. If you crave something sweet in the middle of the afternoon, there’s a chance this craving is stronger when you’re at work, says Anna Konova, director of the Addiction and Decision Neuroscience Laboratory at Rutgers University in New Jersey. Food cravings are sometimes caused by the ambivalence or tension between desiring a food and wanting to control food intake. It’s assumed, a study says, that women in par- ticular resolve this by not hav- ing the food in question – which increases their chance of craving it as they’re more likely to notice cues. Also negative moods can trigger more eating and, for some, become an eat- ing binge. CULTURAL CONDITIONING PSYCHOLOGICAL There is evidence sug- gesting that the trillions of bacteria in our guts can manipulate us to crave, and eat, what they need - which isn't always what our body needs. microbes are looking out for their own interests, says Athena Aktipis, assistant profes- sor at Arizona State University’s department of psychology. And they’re good at doing this. But if you eat a diet with lots of complex carbohy- drates and fibre, you will cultivate a more diverse microbiome, Aktipis says. This probably means that a healthy diet, which leads to a healthy microbiome, means you crave healthy food. MICROBE MANIPULATION

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Page 1: gut bacteria provoke craving to suit their interests ... · sure to a variety of external cues, such as the sight and thought of foods (like sweets, snacks, alcohol). ... where a

Food craving is usuallydescribed as a strong motiva-tion or intense desire or urgeto eat a specific food. Often,craving is also referred to as

an urge to eat something even whenthere is no metabolic need. It is inter-esting to note that many of the foodsfrequently craved are high in carbohy-drate and fats and mostly foods whichare processed. Food cravings haveoften been associated with high bodymass index (BMI) and associated con-ditions which are predominant riskfactors for non-communicable dis-eases. Therefore, there is a surge inthe interest to explore the nutritionaland health impacts of food cravings.Are food cravings really a malfunc-tion or a menace? What’s the mysterybehind them?

WWHHAATT CCAAUUSSEESS FFOOOODD CCRRAAVVIINNGGSS??

The true picture of food craving iscomplex and there are numerous theo-ries about it. The underlying causes ofcraving may be multiple — includingpsychological, conditioning, emotion-al, sensory and food imaging, to namea few. One of the most researched fac-tors as a possible trigger for food crav-ings is ‘mood’. Depressed and stressedindividuals or sleep deprived individ-uals can also suffer cravings and endup in binge eating.

The addiction literature focused con-siderable attention on the relation-ship between cravings and the expo-sure to a variety of external cues,such as the sight and thought of foods(like sweets, snacks, alcohol).Cravings have also been depicted asseasonal affective disorders, as somepeople experience increased cravingsfor sweet carbohydrate and fat-richfoods as winter approaches.

As is known our gut has a variedspecies of microbes. These microbesare constantly under selective pres-sure to increase their fitness andresearch suggests they could bemanipulating the host eating behav-iour. Microbes could constantly lookfor foods that they need to thrive on orcould demand the foods that suppresstheir competitors. These activities ofmicrobes could end up prompting thehost individuals to opt for certainfoods or even crave them. Forinstance, sugar/sweet craving canincrease with inflammation promot-ing gut bacteria, which are unhealthy.In contrast, National Institute ofNutrition studies have shown thathigh fat diets and high carbohydratediets alter gut microbiota which mayhave an effect on neuro transmittersthat could in turn affect cognition andmood. How this can help prevent crav-ing is yet to be established.

AARREE TTHHEE CCRRAAVVIINNGGSS FFOORR SSAAMMEE

FFOOOODDSS CCAAUUSSEEDD BBYY SSAAMMEE FFAACCTTOORRSS??

Craving the same food could have dif-ferent mechanisms in different indi-viduals and at different times.Craving a particular food, say potatowafers, could be caused by the percep-tion that these are often depicted asforbidden foods (unhealthy/junkfoods). Attempts to restrain their eat-ing could trigger increased food crav-ings.

Studies also show that diet composi-tion and macronutrient intake regula-tion also play a role in craving sweet-tasting, palatable foods. It has alsobeen observed by some researchersthat preference for a particularmacronutrient is influenced by theprior macronutrient composition of

the diet. If a specific appetite for a par-ticular macronutrient does exist thenremoving that macronutrient fromthe diet should cause a selective sub-sequent increase in the consumptionof, and possibly in susceptible individ-uals’ “craving” foods that are rich inthat macronutrient.

CCAANN CCRRAAVVIINNGG BBEE MMEEAASSUURREEDD??

Scientists around the globe have triedout many behavioural methods tomeasure craving, the most commonapproach appears to be self-reportingof participants about their craving apre-determined list of foods. Studiesshow that the highly craved foods arecategorised into four types — high-fatfoods, sweets, starchy carbohydratefoods (like noodles, potato chips) andfast-foods.

WWHHAATT IISS IITT IINN IINNDDIIAA??

There are hardly any systematic sci-entific studies. The Indian economicand epidemiologic transition isreflected in the dietary habits ofIndians, where a shift from home-made nutritious foods to easily acces-sible and palatable processed food isvisible. Increasing dietary diversity isthe current priority for Indians, andcurrently high amounts of starch, fatand little amounts of fibre and proteinare consumed across all age and gen-der groups. The consumption ofmonotonous diets has also been asso-ciated with craving carbohydrate andfat rich foods.

In addition, marketing foods onlinewith attractive discounts makes indi-viduals to crave more. It is an interest-ing observation that cravings for car-bohydrate and fat rich foods does notoccur during regular mealtimes;instead, they primarily occur duringsnack time. It has also been seen thatnocturnal sleep is associated withincreased food cravings and therebymaking the BPO and shift employeesthe most affected and vulnerable seg-ments of the population.

SSTTRRAATTEEGGIIEESS TTOO RREEDDUUCCEE FFOOOODD

CCRRAAVVIINNGGSS -- DDOO TTHHEEYY WWOORRKK??

To date, a handful of studies havefocused on strategies to reduce foodcravings. Studies have generallyshown that craving-reduction strate-gies, such as thought suppression (try-ing not to think about the craved food)or cue-exposure response prevention(presenting an individual with thecraved food but not allowing them toeat it) are not very successful.

Thus there is a need to seeknew and different cravingreduction techniques.

Alternatively, expertsand nutritionists sug-gest a number of sim-ple measures thatcan help keep foodcravings at bay.Being physicallyactive, drinkingplenty of water,c o n s u m i n gmicronutrientand fibre-

rich fruits and vegetables as part ofdaily diet may help curb craving.Other tips include trying to consumehealthy, natural and minimallyprocessed foods when in stress,maintaining a balanced diet, main-taining mealtime and following asimilar healthy diet pattern dailyand small but frequent mealsand eating mindfully.

(The author isdirector, National

Institute ofNutrition,

Hyderabad)

Food cravings are linked toweight gain and attendant ail-ments. The best way to fight

cravings is to de-condition ourselves,which is to remove the stimulus thattriggers the response, says clinicalnutrition and metabolism expertJohn W. Apolzan in an email inter-view to DC. He is director atPennington Biomedical ResearchCentre, Louisiana State University

System, USA.

Why do we crave high-caloriefoods that add to weight gain?All foods can lead to weight gain ifconsumed to excess. However, moreenergy-dense foods do tend to leadto weight gain. Further, these itemsare filled with sugar and fat whichare the macronutrients typicallycraved. Overall, chocolate tends tobe the most craved food item.

You refer to ‘conditioningresponse’ to explain food craving.But it’s usual for pregnantwomen to crave a variety of foodsand the popular notion is it mayhave to do with deficiencies?Yes often with palatable food it is aconditioning response. However,there is likely a different mecha-nism (or mechanisms) at play forthose that are malnourished and/orhave deficiencies. The conditioningresponse would not hold true ifsomeone was protein deficient andattempting to over-consume energyto meet their protein needs/require-ments.

Have you observed any link tocraving in the ambivalence

between one desiring a foodand wanting to control its

intake? Or the cravingowes to a dilemma: to

eat or not to eat? I am not 100 per cent

sure of the ques-tion. Actually

energy restriction decreases crav-ings. I think it is important to notethat we found it is the frequency ofconsuming food items versus theamount that was associated withcravings (Obesity 2017).

Of course it is natural to want toeat a variety of foods includingthose that may be less healthy. Thekey is just to do so in moderation interms of amount and frequency.Thus like much of life, it is trulyabout finding a happy, healthy medi-um.

Would you say culture and psy-chology play crucial roles in trig-gering specific food cravings?I think culture and psychology playrather large roles in triggering spe-cific food cravings. You’re not goingto crave a food you’ve never tasted.Further conditioning likely occursdue to the regions culture and psy-chology.

What are best possible ways totackle craving, especially becausea whole lot of lifestyle diseasesare linked to reckless eatinghabits? Decreasing energy intake throughlifestyle interventions has beenshown to be successful in reducingcravings. Nearly all weight lossdiets lead to decreases in food crav-ing. So the first would be weightloss. Secondly with conditioningmodel of food cravings, one would‘decondition’ oneself. If someoneeats a bowl of ice cream nightly dur-ing a specific TV programme thenyou would try and get him/her to

stop the stimulus (i.e.watching the televisionprogramme). Go for awalk, go to the gym andso on.

DR HEMALATHA R.

PAGE

13DECCAN CHRONICLE

During weight loss treatment, reductions inthe frequency of consuming certain foodsresulted in decreased cravings for those

foods. — John W Apolzan and team D C

SUNDAY | 2 JUNE 2019 | THIRUVANANTHAPURAM

DisCourse

DUMP CRAVINGSFood cravings ruin health because they are triggered by external cues rather than

genuine demands of the body. Cultural and psychological factors also aid craving. Again,gut bacteria provoke craving to suit their interests rather than that of the body

Mystery, menace or a malfunction

‘You are not going to cravefood you never tasted’

One of the most researched factors as a possible trigger for foodcravings is mood . Depressed and stressed individuals or sleep deprived

individuals can also suffer cravings and end up in binge eating.

It is natural to want to eat a variety of foodsincluding those that may be less healthy. Thekey is just to do so in moderation in terms of

amount and frequency

JOHN W. APOLZAN

CUT YOURCRAVINGSince our environ-ment is full of cuesthat could tap into ourcravings, such asadvertising and pho-tos on social media,overcoming them isn’tso straightforward.Research has foundthat one of the mosteffective ways to curbcravings is to cut thecraved food from ourdiet, which runscounter to the argu-ment that we cravewhat we need.

THE CUES

Dogs drool at the hint of food. Not just that, pets exhibit signs of cravingbefore regular food time. If one alwayseats popcorn while watching favourite TVshow, it’s likely cravings for popcorn willincrease whenever one watches it. Theafternoon slump is another example ofthis response in practice. If you cravesomething sweet in the middle of theafternoon, there’s a chance this craving isstronger when you’re at work, says AnnaKonova, director of the Addiction andDecision Neuroscience Laboratory atRutgers University in New Jersey.

Food cravings are sometimescaused by the ambivalence ortension between desiring afood and wanting to controlfood intake. It’s assumed, astudy says, that women in par-ticular resolve this by not hav-ing the food in question –which increases their chance ofcraving it as they’re more likelyto notice cues. Also negativemoods can trigger more eatingand, for some, become an eat-ing binge.

CULTURAL CONDITIONING PSYCHOLOGICAL

There is evidence sug-gesting that the trillionsof bacteria in our gutscan manipulate us tocrave, and eat, whatthey need - which isn'talways what our bodyneeds. microbes arelooking out for their owninterests, says AthenaAktipis, assistant profes-sor at Arizona StateUniversity’s departmentof psychology. Andthey’re good at doingthis.But if you eat a diet withlots of complex carbohy-drates and fibre, you willcultivate a more diversemicrobiome, Aktipissays. This probablymeans that a healthydiet, which leads to ahealthy microbiome,means you crave healthyfood.

MICROBE

MANIPULATION